[backend] migration errors keep coming out in travis ci

[ByungHeeCha]

https://stackoverflow.com/questions/45984380/travis-ci-django-build-fails
I think it is problem of difference between sqlite and mysql. I think we need to update .travis.yml to resolve this error.

[hadooboo]

I'd like to resolve this error too.. but the script dealing with database should be written in my vm server. I don't know we can handle this on travis.yml

[ByungHeeCha]

https://stackoverflow.com/questions/28035119/should-i-be-adding-the-django-migration-files-in-the-gitignore-file
I think we shouldn't put migration file in .gitignore

[hadooboo]

but the db travis make is test_(db_name), so if there is no migration process, then no db exists..