Implement support for CouchDB

[dadrus]

Implement an extension to JPA-Unit which supports all the JPA-Unit tools with CouchDB.

The idea is to be able to use JPA providers, which support NoSQL databases, thus to be able to reuse (to a certain extent) existing code and test implementation when switching between different data base types or when using different types of data bases (polyglot persistence) in one project.

CouchDB seems to be supported by following JPA provider:

• EclipseLink
• Hibernate OGM (Experimental)
• Kundera