Bumps [acorn](https://github.com/acornjs/acorn) from 6.4.0 to 6.4.1. **This update includes a security fix.**
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](https://github.com/acornjs/acorn/compare/6.4.0...6.4.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

* Remove Address.toPayable

* Add changelog entry

* Make IERC721 contracts interfaces instead

* Bump minimum compiler version for IERC721

* Remove ERC721.burn(owner, tokenId)

* Remove ERC721._checkOnERC721Received from the contract's API

* Fix linter error

* Remove Escrow and PullPayment withdrawWithGas, replace for withdraw

* Add changelog entry

* Add reentrancy notice

* Remove Roles

* Add AccessControl and tests

* Removed IAccessControl

* Add RoleGranted and RoleRevoked events

* Make roles grantable and revokable regardless of their previous status

* Fix typo

* Add documentation

* Cleanup tests

* Add enumeration tests

* Add _setRoleAdmin tests

* Fix lint error

* Fix AccessControl link in docs

* WIP on access control guide

* Rename getRoleMembersCount

* Add tests for new role admin

* Make AccessControl GSN compatible

* Update access control guide

* Rename admin to adminRole

* Rename roleIds to roles

* Add 'operator' to RoleGranted and RoleRevoked events.

* Only emit events if the roles were not previously granted/revoked

* Uncomment expectEvent.not tests

* Rename operator to sender

* Add changelog entry

* Move Pausable into utils

* Move Strings into utils

* Move Counters into utils

* Move SignedSafeMath into math

* Remove ERC1046

* Make ERC20Snapshot.snapshot internal

* Move ERC20Snapshot into ERC20

* Add drafts deprecation notice

* Remove drafts directory

* Add changelog entry

* Apply suggestions from code review

Co-Authored-By: Francisco Giordano <frangio.1@gmail.com>

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

* Remove Ownable.isOwner.

* Remove ownable behavior from tests

* Make Escrow use Ownable instead of Secondary

* Migrate GSNRecipientERC20Fee to Ownable

* Remove Secondary

* Move Ownable to access directory

* Remove mentions of Secondary

* Add changelog entry

* Move Ownable tests to access

* Remove unused mock

* Remove ERC20._burnFrom

* Add changelog entry

Bumps [@openzeppelin/cli](https://github.com/OpenZeppelin/openzeppelin-sdk) from 2.7.1 to 2.7.2.
- [Release notes](https://github.com/OpenZeppelin/openzeppelin-sdk/releases)
- [Commits](https://github.com/OpenZeppelin/openzeppelin-sdk/compare/v2.7.1...v2.7.2)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Bumps [@openzeppelin/test-helpers](https://github.com/OpenZeppelin/openzeppelin-test-helpers) from 0.5.4 to 0.5.5.
- [Release notes](https://github.com/OpenZeppelin/openzeppelin-test-helpers/releases)
- [Changelog](https://github.com/OpenZeppelin/openzeppelin-test-helpers/blob/master/CHANGELOG.md)
- [Commits](https://github.com/OpenZeppelin/openzeppelin-test-helpers/compare/v0.5.4...v0.5.5)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Bumps [@openzeppelin/gsn-provider](https://github.com/OpenZeppelin/openzeppelin-gsn-provider) from 0.1.9 to 0.1.10.
- [Release notes](https://github.com/OpenZeppelin/openzeppelin-gsn-provider/releases)
- [Changelog](https://github.com/OpenZeppelin/openzeppelin-gsn-provider/blob/master/CHANGELOG.md)
- [Commits](https://github.com/OpenZeppelin/openzeppelin-gsn-provider/compare/v0.1.9...v0.1.10)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Bumps [acorn](https://github.com/acornjs/acorn) from 6.4.0 to 6.4.1.
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](https://github.com/acornjs/acorn/compare/6.4.0...6.4.1)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Remove crowdsales from sidebar documentation, add links to old version

* Remove mentions of Crowdsales from the documentation

Bumps [solhint](https://github.com/protofire/solhint) from 3.0.0-rc.3 to 3.0.0-rc.5.
- [Release notes](https://github.com/protofire/solhint/releases)
- [Changelog](https://github.com/protofire/solhint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/protofire/solhint/commits)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

* Make ECDSA.recover revert on error

* Removed unused test

* Remove duplicate line

* Add tests for invalid signatures

* Fix linter errors

* Add changelog entry

* Use bytes32 explicitly for Create2.computeAddress(), to force users cache hash of the bytecode

* Remove only from test :)

In https://github.com/OpenZeppelin/openzeppelin-contracts-ethereum-package/pull/76, we are rearranging the erc721metadata contract storage layout, so the new variable is added at the end. This commit applies the same change to the vanilla contracts repository, so migration from 2.5 to 3.0 is easier for users using the transpiler.

Bumps [mocha](https://github.com/mochajs/mocha) from 7.0.1 to 7.1.0.
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mochajs/mocha/compare/v7.0.1...v7.1.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [@openzeppelin/test-environment](https://github.com/OpenZeppelin/openzeppelin-test-environment) from 0.1.2 to 0.1.3.
- [Release notes](https://github.com/OpenZeppelin/openzeppelin-test-environment/releases)
- [Changelog](https://github.com/OpenZeppelin/openzeppelin-test-environment/blob/master/CHANGELOG.md)
- [Commits](https://github.com/OpenZeppelin/openzeppelin-test-environment/compare/v0.1.2...v0.1.3)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [solhint](https://github.com/protofire/solhint) from 3.0.0-rc.2 to 3.0.0-rc.3.
- [Release notes](https://github.com/protofire/solhint/releases)
- [Changelog](https://github.com/protofire/solhint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/protofire/solhint/commits)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [@openzeppelin/cli](https://github.com/OpenZeppelin/openzeppelin-sdk) from 2.7.0-rc.2 to 2.7.1.
- [Release notes](https://github.com/OpenZeppelin/openzeppelin-sdk/releases)
- [Commits](https://github.com/OpenZeppelin/openzeppelin-sdk/compare/v2.7.0-rc.2...v2.7.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [openzeppelin-docs-utils](https://github.com/OpenZeppelin/docs-utils) from `af3466e` to `459f171`.
- [Release notes](https://github.com/OpenZeppelin/docs-utils/releases)
- [Commits](https://github.com/OpenZeppelin/docs-utils/compare/af3466e2342fa004288b1b77841fa519148a879b...459f1710a07ec02cbd683cab4800c32a07aed274)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [eslint-utils](https://github.com/mysticatea/eslint-utils) from 1.4.0 to 1.4.3. **This update includes security fixes.**
- [Release notes](https://github.com/mysticatea/eslint-utils/releases)
- [Commits](https://github.com/mysticatea/eslint-utils/compare/v1.4.0...v1.4.3)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [handlebars](https://github.com/wycats/handlebars.js) from 4.1.2 to 4.7.3. **This update includes a security fix.**
- [Release notes](https://github.com/wycats/handlebars.js/releases)
- [Changelog](https://github.com/wycats/handlebars.js/blob/master/release-notes.md)
- [Commits](https://github.com/wycats/handlebars.js/compare/v4.1.2...v4.7.3)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Rename CREATE2 argument from bytecodeHash to bytecode and add new method for precomputed bytecode hash (#2087)

* Rename CREATE2 argument from bytecodeHash to bytecode and add new method for precomputed bytecode hash

* Remove only from test

* Fix linter error

* Initial migration to Solidity 0.6.x - v3.0 first steps (#2063)

* Initial migration, missing GSN, 721, 777 and Crowdsales.

* Add _beforeTokenOperation and _afterTokenOperation.

* Add documentation for hooks.

* Add hooks doc

* Add missing drafts

* Add back ERC721 with hooks

* Bring back ERC777

* Notes on hooks

* Bring back GSN

* Make functions virtual

* Make GSN overrides explicit

* Fix ERC20Pausable tests

* Remove virtual from some view functions

* Update linter

* Delete examples

* Remove unnecessary virtual

* Remove roles from Pausable

* Remove roles

* Remove users of roles

* Adapt ERC20 tests

* Fix ERC721 tests

* Add all ERC721 hooks

* Add ERC777 hooks

* Fix remaining tests

* Bump compiler version

* Move 721BurnableMock into mocks directory

* Remove _before hooks

* Fix tests

* Upgrade linter

* Put modifiers last

* Remove _beforeTokenApproval and _beforeOperatorApproval hooks

* Add note about gas costs

* Update wording

This reverts commit e7bded65.