Update M7-8 interface floating rupture MFD parameters

The MFD parameters for the M7-8 interface floating ruptures were not updated to the full catalog values used for the gridded seismicity models. Updating thi value, and possibly adding upper and lower branches should be possible with move to point source representation. See #35 (closed)

added ERF label

assigned to @pmpowers

mentioned in merge request !72 (merged)

mentioned in commit 9da01206

closed with merge request !72 (merged)