Rename Interface and Enum for proper Java conventions.
See: http://www.vertigrated.com/blog/2011/02/interface-and-class-naming-anti-patterns-java-naming-convention-tautologies/
Simplified JUnit tests by setting up a @Before method
Proper variable naming.
Correct spelling of "Referer" -> "Referrer", Someone has to start and
fix the mispelling introduced a few decades ago.

See: https://gist.github.com/whowantstolivefo/5004366
Bump to version 1.1.0
Rename artifactId and name to piwik-java-tracking