Fix
* Apparently only Python2 needs *mu tag, Python3 should use *m one ([`3754db1`](https://github.com/ssc-oscar/oscar.py/commit/3754db15c043a5e4f181b6e788ba5259c7b1fbc2))
* Use wide unicode tags for wheels (cp27mu and cp36mu, as most Linux distributions use those) ([`afc609b`](https://github.com/ssc-oscar/oscar.py/commit/afc609b98012196ce7d7093a5a94b777642e83cf))