Added Repo-Interface with Test class for saving patient into postgresql database.

opp/core/pom.xml

opp/core/src/main/java/Address.java

opp/core/src/main/java/Gender.java

opp/core/src/main/java/Id.java

opp/core/src/main/java/Patient.java

opp/core/src/main/java/Person.java

opp/core/src/main/java/Repository.java

opp/jdbc-repo-impl/pom.xml

opp/jdbc-repo-impl/src/main/java/JDBCRepository.java

opp/jdbc-repo-impl/src/test/java/Tests.java

opp/pom.xml