Add JPA Plugin

This change updates the builder to publish the Play JPA plugin during
the publishing of the auto reconfiguration.  These two JARs are
closely linked and released as a single project, so publishing them
both at the same time is appropriate.  In addition, this change
updates the README file with the fact that 0.7.1 has been published.

[#53775581]
Merge 53775581-add-jpa-plugin to master

[Completes #53775581]