TEST: unit test for timestamp GC
TEST: unit test for timestamp GC

DrDaveD/cvmfs,djw8605/cvmfs,trshaffer/cvmfs,cvmfs/cvmfs,cvmfs/cvmfs,alhowaidi/cvmfsNDN,MicBrain/cvmfs,Moliholy/cvmfs,reneme/cvmfs,trshaffer/cvmfs,MicBrain/cvmfs,trshaffer/cvmfs,DrDaveD/cvmfs,Moliholy/cvmfs,Gangbiao/cvmfs,djw8605/cvmfs,cvmfs/cvmfs,djw8605/cvmfs,djw8605/cvmfs,trshaffer/cvmfs,alhowaidi/cvmfsNDN,DrDaveD/cvmfs,Moliholy/cvmfs,reneme/cvmfs,cvmfs-testing/cvmfs,reneme/cvmfs,MicBrain/cvmfs,cvmfs/cvmfs,DrDaveD/cvmfs,reneme/cvmfs,cvmfs-testing/cvmfs,Moliholy/cvmfs,DrDaveD/cvmfs,reneme/cvmfs,cvmfs-testing/cvmfs,alhowaidi/cvmfsNDN,MicBrain/cvmfs,DrDaveD/cvmfs,Gangbiao/cvmfs,cvmfs-testing/cvmfs,trshaffer/cvmfs,cvmfs/cvmfs,Gangbiao/cvmfs,MicBrain/cvmfs,cvmfs-testing/cvmfs,Moliholy/cvmfs,cvmfs/cvmfs,Gangbiao/cvmfs,djw8605/cvmfs,DrDaveD/cvmfs,alhowaidi/cvmfsNDN,Gangbiao/cvmfs,cvmfs/cvmfs,alhowaidi/cvmfsNDN