Revert "Adds a wrapper around abort function to add JSON Content-Type."

This reverts commit 8aacd39d91777f10153424e47cbb5d1c2833491a.

Conflicts:
	tests/__init__.py
	tests/test_exceptions.py
Merge pull request #228 from goodscloud/remove-jsonhttpexception-dependency

Revert "Adds a wrapper around abort function to add JSON Content-Type."