Remove beta tag from truffle

truffle@beta uses old solc 0.4.11
truffle main branch uses most up to date 0.4.15

Remove token.finishMinting() from default finalization

Sync yarn.lock file with package-lock.json

1. deleted node_modules
2. ran `npm install`
3. deleted yarn.lock
4. ran `yarn import`

Upgrade solidity coverage to ^0.2.1

Add Transfer event when token is minted

Move truffle-hdwallet-provider to devDependencies

Change crowdsales to use timestamps instead of block numbers #350

Added contracts/token/BurnableToken.sol

Fix typo in SafeMath doc

Add missing parentheses in modifier

tests

Remove return values of pause() and unpause() of Pausable

Add complex crowdsale example #331

Move examples to separate directory

Upgrade truffle to 3.4.6