Created basic register subject tests.
updated autheticateWithJson to use JSON. Also updated test to serialize using GSON so that null fields were not serialized by default.
added quickcheck theory
Revert "added quickcheck theory"

This reverts commit bf5f10ce150039c23502c6690993375d00124aec.
added validation for subject registration body content.
test empty message
test double byte strings in reference and message.
Merge pull request #1 from limsim/register-subject-tests

Register subject tests