Composer Requirements Not Included When Running Code Sniffer

[justinyost]

The Composer Requirements are not included when running the code sniffer.

I realize this is by design in the before script: https://github.com/FriendsOfCake/travis/blob/master/before_script.sh#L5

However it makes it that much more work if I want to use a custom Code Sniffer Standard, since I have to add a line to include that custom standard.

I'm basically wondering if it's possible to change this to at least include the added Composer Requirements when running the Code Sniffer as well?

[dereuromark]

Feel free to provide a PR here.