Refactor cache layer to use get/save wrappers and squash any exceptions
Refactor cache layer to use get/save wrappers and squash any exceptions

- This allows us to run without caching.  Currently we consider caching via
  redis to be a feature not a requirement.  Therefore, this change allows us to
  continue running even if the cache is configured but not reachable.

pluralsight/guides-cms,pluralsight/guides-cms,paulocheque/guides-cms,pluralsight/guides-cms,paulocheque/guides-cms,paulocheque/guides-cms