added OracleJDK7, OpenJDK6, and OpenJDK7 to Travis CI configuration.
added OracleJDK7, OpenJDK6, and OpenJDK7 to Travis CI configuration.

tomgullo/rexster,alszeb/rexster,tomgullo/rexster,alszeb/rexster,tingletech/rexster-tomcat,tingletech/rexster-tomcat,alszeb/rexster,tomgullo/rexster,tomgullo/rexster,tingletech/rexster-tomcat,alszeb/rexster