Create a dev-friendly test app from the ioFog test message generator project

The test message generator project has huge potential to help developers test their edge apps locally.

Modify the project (https://github.com/iotracks/test-message-generator) to make it easy to import the test server as a test dependency in JVM projects.

The service should support acceptance of IoMessage types and send them to connected applications. It should also support acceptance of config JSON objects and send those configs to local running edge applications.

Those two requirements should be sufficient for an initial usage.