Add custom fixer for discussed styling

[enebe-nb]

This will correctly catch this 2 styles:

• Array syntax is [] or [ 'key' => 'value' ] (spaces after opening bracket and before closing bracket)
• Multi line operations: The operator should be prepended to the front of the next line.

To add a travis check on code styling a dev dependency must be added. Since php can't reference classes from a phar archive. If you like then i could add this, just tell me.

Also, i sent this merge to cs-fixer branch to prepare it to merge in master after all styling is discussed.

[enebe-nb]

Sorry, before i downloaded an old cs-fixer version and got a few errors while using it directly. Travis integration is now added and an extra dependency is not needed.

This code will fail on travis, since the code doesn't follow the styling yet, but this will allow to see the travis' feedback.

[svpernova09]

This looks good from here. @rocketpastsix will you have a look and double check. Thanks!

[matthewtrask]

Looks good to me. @svpernova09