Revert "Revert "Merge pull request #31 from LuisMuniz/master""

Reintroduce changes for the heartbeat functionality.

This reverts commit 62bafa603ac462d1fdd68830a11f9555027d5d7a.
Remove hibernate dependency, and only init hibernate session if hibernate is present.
Use connection default enums, and remove project files.
Fix error handling around retrieving the persistence interceptor bean.
Updated docs for requestedHeartbeat, and updated changelog.
Release 2.0.5