Tests

add gulp tasks for eslint:
```
gulp eslint
```
and jsbeautify
```
gulp js-beautify # add --write if you want it to automatically fix files
```

Both are run by `npm test`

Please fix the eslint and jsbeautify errors.

Please add you lib's specific tests to `npm test` in package.json
```
./node_modules/gulp/bin/gulp.js lint && cmd
```

Please also be hook up to travis.