update event logging for watchlist star to use new schema

https://meta.wikimedia.org/w/index.php?title=Schema:MobileBetaWatchlist&oldid=5235429

add isStable field
remove editCount field

Change-Id: I827a5b21a23a43af403d96e383104418a3983547
Updated Ruby gems

Change-Id: I52682a4ac3c7524832396ee9b80f7d7bee4a8034
Merge "update event logging for watchlist star to use new schema"
Merge "Updated Ruby gems"