add test for CVMFS_CONFIG_REPO_REQUIRED
add test for CVMFS_CONFIG_REPO_REQUIRED

cvmfs/cvmfs,cvmfs/cvmfs,cvmfs/cvmfs,trshaffer/cvmfs,DrDaveD/cvmfs,DrDaveD/cvmfs,trshaffer/cvmfs,Gangbiao/cvmfs,cvmfs/cvmfs,Gangbiao/cvmfs,DrDaveD/cvmfs,DrDaveD/cvmfs,Gangbiao/cvmfs,Gangbiao/cvmfs,cvmfs/cvmfs,trshaffer/cvmfs,cvmfs/cvmfs,DrDaveD/cvmfs,djw8605/cvmfs,DrDaveD/cvmfs,trshaffer/cvmfs,djw8605/cvmfs,cvmfs/cvmfs,djw8605/cvmfs,djw8605/cvmfs,trshaffer/cvmfs,Gangbiao/cvmfs,djw8605/cvmfs,DrDaveD/cvmfs