specify gem verisons
add .ruby-verison file
small modify, remove redundant codes
add sponsor delete, change solutions_path name, try to fix calendar show, fix sign out problem
Merge commit '34685ca557c48ea8fd7b33620e6ad95374ac4f08'

* commit '34685ca557c48ea8fd7b33620e6ad95374ac4f08':
  Fix submodule
  Test fixes
  Sqlite3 for dev database
  Added mailmap