GOSSIP-81 Move Jackson and UDP to their own modules

Part of what makes this work is the test implementation of TransportManager.

This PR is pretty straightforward. A few gotchas though:
* A message signing test was moved into `JacksonTests` because that is
  where the signing actually happens.
* A CRDT serializing test was moved there as well. It's the best place
  for now.
* No UDP tests at all. I plan to fix that in a bit. Reasoning is that it is
  difficult to test any TransportManager implementation without bring up
  a full stack. I plan to address this in the future (GOSSIP-83).
* Simple round trip Jackson serialization tests.

gossip-transport-udp/pom.xml

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ 	Licensed to the Apache Software Foundation (ASF) under one or more
+ 	contributor license agreements.  See the NOTICE file distributed with
+ 	this work for additional information regarding copyright ownership.
+ 	The ASF licenses this file to You under the Apache License, Version 2.0
+ 	(the "License"); you may not use this file except in compliance with
+ 	the License.  You may obtain a copy of the License at
+ 	
+ 		http://www.apache.org/licenses/LICENSE-2.0
+ 	
+ 	Unless required by applicable law or agreed to in writing, software
+ 	distributed under the License is distributed on an "AS IS" BASIS,
+ 	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ 	
+ 	See the License for the specific language governing permissions and
+ 	limitations under the License.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>org.apache.gossip</groupId>
+    <artifactId>gossip-parent</artifactId>
+    <version>0.1.3-incubating-SNAPSHOT</version>
+    <relativePath>../pom.xml</relativePath>
+  </parent>
+  
+  <name>Gossip UDP Transport</name>
+  <artifactId>gossip-transport-udp</artifactId>
+  <version>0.1.3-incubating-SNAPSHOT</version>
+  
+  <dependencies>
+    <dependency>
+      <groupId>org.apache.gossip</groupId>
+      <artifactId>gossip-base</artifactId>
+      <version>0.1.3-incubating-SNAPSHOT</version>
+    </dependency>
+  </dependencies>
+    
+</project>