jpa-unit rdbms extension requires the usage of javax.persistence.jdbc.user and -password

[dadrus]

javax.persistence.jdbc.user and javax.persistence.jdbc.password are not always required to be configured. Some rdbms support setting of user and password as part of the jdbc url. In such cases the jpa-unit rdbms extension cannot be used. It simply ignores the persistence.xml configuration und thus is not executed.

The solution is simple: just delete the verification of the presence of the both aforesaid properties in the `persistence.xml'.

As a workaround for the test code affected by this issue (as long as the fix is not avalable), configure the aforesaid properties and remove corresponding settings from the jdbc url.

[dadrus]

solved in #40