Drop support of django 1.10 and 1.9 and Python 3.4

[NyanKiyoshi]

Graphene no longer supports those versions and django doesn't either, 1.9 and 1.10 reached EOL in 2017.

We shouldn't support them anymore, anyone still using one of these version should upgrade to the latest LTS which still provide security and bug fixes.

Supporting them requires us more work as some behavior are different between versions and we can't be sure it will actually work as expected in production as graphene doesn't support them.

Same thing with Python 3.4, we can't say for sure it will work, graphene doesn't support it anymore and neither Python does (since March 2019).