Allow content-type header with charset on test.

[ceritium]

Specs fails when the Content-Type is "text/plain; charset=utf-8"

[codecov-commenter]

Codecov Report

Merging #501 (0859b5d) into master (a93060e) will not change coverage.
The diff coverage is n/a.

❗ Current head 0859b5d differs from pull request most recent head 4952680. Consider uploading reports for the commit 4952680 to get more accurate results

@@           Coverage Diff           @@
##           master     #501   +/-   ##
=======================================
  Coverage   87.50%   87.50%           
=======================================
  Files          18       18           
  Lines        1257     1257           
=======================================
  Hits         1100     1100           
  Misses        157      157           

---

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 a93060e...4952680. Read the comment docs.

[SamSaffron]

Thanks heaps!