* update dep for java jersey1, jersey2
* update sbt dependency for jersey2
* update dep for java okhttp-gson, resteasy, resttemplate
* update dep for java retrofit 1.x, 2.x
* update java petstore samples
* Add support for Spring's RestTemplate in Java client codegen
Resolves#1176
* Update all Java samples to include change for Jackson enums
Currently enums are deserialized from a String value with an
explicit @JsonCreator. However, they are not being serialized with
this String value. This change introduces the @JsonValue annotation
on the toString() method of enums, so they will be serialized as a
String with the correct value.