Evolution:

https://github.com/jgp/hudson_campfire_plugin ->
https://github.com/jlewallen/jenkins-hipchat-plugin ->
https://github.com/lechat-im/jenkins-lechat-plugin

Building and Installing:

1. Install maven 3

2. $ mvn clean

3. $ mvn package

4. target/lechat.hpi is the plugin, upload it to Jenkins