Bugfix tests

- Fix typo in Overlap Error (Closes JIRA CBDEUCE-211)
- Fix upload block should return X-Block-Reference-Count and X-RefModified (Closes JIRA CBDEUCE-255)
- Fix bug in Block Collection on_post, error message specified PUT instead of POST
I've switched it back locally, and it seems to work just fine. Might have been from when I was trying to diagnose something else...don't know. I'll have another push against this once I finish the testing