Update README.md
Update PersistentDao.java

Just reinstated drop tables method so mvn test doesn't fail
Update AmberPersistenceDaoTest.java

Removed index creation from tests - they are not yet necessary and cause tests to fail
Update AmberGraph.java

Turned off auto commit - it's not ready yet and just causes tests to take an extremely long time to run.
Update AmberGraphDaoTest.java

Test requires id_generator table
Update AmberGraphDaoTest.java

Tests need all the tables
Updated pom.xml in order to deploy to nla maven repository
Changed the config to deploy the library to nexus.
Merge branch 'master' of https://github.com/nla/amberdb
merged the latest changes from the master branch.