remove uesless env attribute from allow_failures
remove uesless env attribute from allow_failures

this isn't needed here. We specify env + rvm version in our build
matrix. allow_failures only needs to list the rvm version. This is
tested in https://github.com/voxpupuli/puppet-gluster/pull/60 and
documented at
https://docs.travis-ci.com/user/customizing-the-build/#Rows-that-are-Allowed-to-Fail

dhoppe/modulesync_config,dhoppe/modulesync_config,voxpupuli/modulesync_config,voxpupuli/modulesync_config,voxpupuli/modulesync_config,dhoppe/modulesync_config,voxpupuli/modulesync_config,dhoppe/modulesync_config,puppet-community/modulesync_config