Change 5.4 specific array syntax into 5.3

This allows to use UrlMap with Builder and Run which supports
5.3 now.

As a side this adds a travis file which tests on 5.3, 5.4, 5,5 and hhvm.
Merge pull request #11 from henrikbjorn/5.3-support

Change 5.4 specific array syntax into 5.3