Change composer to specifically get dev-master of ez packages
Attempt to fix failing behat tests on travis
Cleanup fix for Behat tests

fpm is provided by php-env, so should not install the system one as well as it will
not be same version as requested via .travis.yml.
Merge pull request #169 from ezsystems/fix_content_bdd_test2

Attempt to fix failing behat tests on travis
Added session folder to .gitignore
Added ExtensibleEzPublishKernel
Updated config irt kernel.root_dir
Adapted behat.yml