add travis and coveralls integration

make tests compatible with php 5.3

remove hhvm from travis

add coveralls integration

use old array syntax for php 5.3 support

add php 5.3 to the allowed failures for now

add build and coverage indicators to readme
This is a testing issue, but the tests should pass on any supported version of PHP.  The library does claim PHP 5.3 support.  We could always change that to 5.4 due to this issue and just be done with it.  Maybe mark in the release notes, "Officially supported on PHP 5.4, should work on PHP 5.3 with unit test failures."