Add Virgo frame cache guess

Currently the frame cache reading makes guesses for the channel names, these need to be updated to also handle Virgo data.

@colm.talbot : I've found the relevant frame types used during O2, we'll also need to get the Virgo channel names right, they use a different naming convention to LIGO.

types={'H1':'H1_llhoft','L1':'L1_llhoft','V1':'V1Online'}# Online
# types={'H1':'H1_HOFT_C00','L1':'L1_HOFT_C00','V1':'V1Online'}# Offline C00
# types={'H1':'H1_HOFT_C01','L1':'L1_HOFT_C01','V1':'V1Online'}# Offline C01
# types={'H1':'H1_HOFT_C02','L1':'L1_HOFT_C02','V1':'V1Online'}# Offline C02

mentioned in merge request !239 (merged)

Closed by !328 (merged)

closed