Graphene v3 support

[mongkok]

close #200

[codecov-commenter]

Codecov Report

Merging #213 into master will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master      #213   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           16        16           
  Lines          256       256           
  Branches        30        30           
=========================================
  Hits           256       256           

Impacted Files	Coverage Δ
graphql_jwt/middleware.py	100.00% <ø> (ø)
graphql_jwt/path.py	100.00% <100.00%> (ø)
...t/refresh_token/management/commands/cleartokens.py	100.00% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1229f4b...28847cd. Read the comment docs.