Snapshot rollback issue

Don't allow user to submit snapshot rollback request
when there are no writable snapshots
Snapshot rollback issue

Don't allow user to submit snapshot rollback request
when there are no writable snapshots
Snapshot rollback issue # 511

Don't allow user to submit snapshot rollback request
when there are no writable snapshots
Snapshot rollback issue # 511

Don't allow user to submit snapshot rollback request
when there are no writable snapshots
Merge branch 'issue#511_snapshot_rollback' of https://github.com/kamal-gade/rockstor-core into kamal-gade-issue#511_snapshot_rollback
Snapshot rollback issue # 511

Don't allow user to submit snapshot rollback request
when there are no writable snapshots
Merge branch 'issue#511_snapshot_rollback' of https://github.com/kamal-gade/rockstor-core into kamal-gade-issue#511_snapshot_rollback
don't show readonly snapshots in the rollback choices table. #511
Merge branch 'issue#511_snapshot_rollback' of https://github.com/kamal-gade/rockstor-core into kamal-gade-issue#511_snapshot_rollback
Add trigger for snapshot add delete and update rollback btn display on
event
Merge pull request #529 from kamal-gade/issue#511_snapshot_rollback

Issue#511 snapshot rollback