docker image for tomcat7 (with Oracle JDK) based off of stackbrew/debian:jessie

Note: For Tomcat 7 with OpenJDK, use mbentley/tomcat7

To pull this image: docker pull markhuyong/docker-tomcat7-oraclejdk

Example usage: `docker run -p 80:8080 -d markhuyong/docker-tomcat7-oraclejdk