Added udp_gateway quick_start.

This code does not pass this test.  In greetingService.waitForOKMessage() of UdpGatewayTest.java, I get the following error:

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Test set: org.switchyard.quickstarts.udp_gateway.UdpGatewayTest
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Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 8.613 sec <<< FAILURE!
sendUdpString(org.switchyard.quickstarts.udp_gateway.UdpGatewayTest)  Time elapsed: 5.033 sec  <<< FAILURE!
junit.framework.AssertionFailedError: Timed out waiting on event queue length to be 1 or greater.
	at junit.framework.Assert.fail(Assert.java:50)
	at org.switchyard.test.MockHandler.waitFor(MockHandler.java:219)
	at org.switchyard.test.MockHandler.waitForOKMessage(MockHandler.java:190)
	at org.switchyard.quickstarts.udp_gateway.UdpGatewayTest.sendUdpString(UdpGatewayTest.java:44)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
	at org.switchyard.test.SwitchYardRunner.run(SwitchYardRunner.java:90)
	at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:59)
	at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.executeTestSet(AbstractDirectoryTestSuite.java:120)
	at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.execute(AbstractDirectoryTestSuite.java:103)
	at org.apache.maven.surefire.Surefire.run(Surefire.java:169)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at org.apache.maven.surefire.booter.SurefireBooter.runSuitesInProcess(SurefireBooter.java:350)
	at org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:1021)