Enable animal-sniffer to check JDK compatibility
Enable animal-sniffer to check JDK compatibility

- Animal Sniffer: http://mojo.codehaus.org/animal-sniffer/
- Also separate "required.java" from "required.jvm" in case we want to
  use something like retrolambda.

zanata/zanata-platform,zanata/zanata-platform,zanata/zanata-platform,zanata/zanata-platform,zanata/zanata-platform,zanata/zanata-platform,zanata/zanata-platform