Maintenance and improvements

89b0582 (HEAD -> master, tag: 2.1.2, origin/master, origin/HEAD) Version bump
7afb1df attribute check handled to avoid exception during module import (#182)
5d7a927 Create django.po (#176)
cd69685 Added 'ACCOUNT_USERNAME_VALIDATORS' check on auth user update (#178)
117cdf6 Merge pull request #179 from lideen/master
e346dfa Moved swedish translation to the correct location
effd621 Update serializers.py (#172)
441b2e9 Adds view for refreshing tokens with cookies (#173)

Special thanks to

Jannis Leidel
Jerin Peter George
Jonas Lidén
Lance.Moe
Michael
Yeh Yen-Ke