Improves java-spark docs and adds docker-config (#45)

* Added Comment

* Added Config

Author: jaisontj

java-spark/Dockerfile

@@ -8,5 +8,6 @@ WORKDIR /spark
 Add . /spark
 
 RUN mvn package
+#Replace target/java-spark-jar-with-dependencies.jar with the name and description specified by the maven-assembly-plugin in your pom.xml
 CMD ["/usr/lib/jvm/java-8-openjdk-amd64/bin/java", "-jar", "target/java-spark-jar-with-dependencies.jar"]
 

java-spark/docker-config.yaml

@@ -0,0 +1,4 @@
+image: "java:<tag>"
+port: 8080
+volume_mounts: null
+env_variables: ["PORT"]