If you don't do this, you'll receive this error:

```
❯ zeppelin npm install zeppelin-solidity
npm WARN saveError ENOENT: no such file or directory, open '/Users/et/package.json'
npm WARN enoent ENOENT: no such file or directory, open '/Users/et/package.json'
npm WARN et No description
npm WARN et No repository field.
npm WARN et No README data
npm WARN et No license field.

+ zeppelin-solidity@1.3.0
updated 1 package in 0.677s
```

Using require for Token preconditions

Add explicit visibility

Make approve method compliant with ERC20

A bunch of small fixes

Merkle proof library with tests and docs

Properly kill background testrpc instance

Just fix typo.

Explicit public visibility on methods

removing trailing whitespace

comments on vesting

Remove indexed declaration of value in Burn event

Fix INITIAL_SUPPLY in SimpleToken example

Use token decimals

Use SafeERC20 to transfer tokens safely

Add OwnershipTransferred event to Ownable contract and its derivatives

Fix Pausable documentation