Wrong error message "invalid JSON" when "RequestDataTooBig" raised

[dotsbb]

Django's request.body might raise RawPostDataException, RequestDataTooBig and UnreadablePostError exceptions which are not related to "invalid JSON".

[coveralls]

Coverage decreased (-3.09%) to 90.756% when pulling a9f34da on dotsbb:fix-too-broad-exception into eb02f87 on graphql-python:master.

[coveralls]

Coverage decreased (-3.09%) to 90.756% when pulling a9f34da on dotsbb:fix-too-broad-exception into eb02f87 on graphql-python:master.

[coveralls]

Coverage increased (+0.03%) to 93.878% when pulling 33b2b42 on dotsbb:fix-too-broad-exception into eb02f87 on graphql-python:master.