S64: added notifications model.
S49:backend part finished
Merge branch 'master' of https://github.com/BdayaNinjas/BdayaAdmin
Revert "Merge branch 'master' of https://github.com/BdayaNinjas/BdayaAdmin"

This reverts commit 6745e79fcb44b9a0d06fa7897576f4b01fdad274, reversing
changes made to 3565629409b023ec29989d65840980b2ffa032c1.
S49: backend finished