Merge pull request #381 from peternewman/trivial-fixes

Add a check for JsonRawValue, fix some licence issues. Enhance and enable the licence enforcer for travis and fix a Python test issue on OS X
Resync with trunk.
Merge branch 'trivial-fixes' of https://github.com/peternewman/ola into trivial-fixes
Add a timestamp to model data filenames so they're unique