Fix to extra SyncSession deletion.
Merge branch 'release-0.12.0' into nalanda-rct2
Merge branch 'nalanda-rct2' of github.com:learningequality/ka-lite into nalanda-rct2
Fix to get_models to include soft-deleted models and devices.
Merge branch 'nalanda-rct2' of github.com:learningequality/ka-lite into nalanda-rct2
Merge branch 'nalanda-rct2' of github.com:learningequality/ka-lite into nalanda-rct2