Merge pull request #42 from spadgett/master

fix testRelativeUriResolutionPut
Allow testPreconditionRequiredStatusCode to run independently

Previously it required testPutRequiresIfMatch, which is only a SHOULD
requirement. Thus if you ran just the MUST group, the test would be
skipped.

This commit changes the test to determine if If-Match is required on its
own without running testPutRequiresIfMatch.

Fixes #41