Merge pull request #13 from hibiyasleep/dev-pr1

missing import: sqlalchemy.exc.IntegrityError
Merge pull request #12 from hibiyasleep/dev-img

logo image modification
Bug fix
Merge branch 'dev' of github.com:relip/depot into dev
Bug fix: fix invalid argument
Merge branch 'dev' of https://github.com/relip/depot into dev