Introduce SpringJUnitTestRunner

Accidentally formatted source as well :-/
Bring mock client creation back to test class
Adds context configuration for integration tests
Adds Servlet API as runtime dependency

The Servlet API is usually provided by Tomcat (and EE servers).
In case of testing this API has to be provided explicitly. The
runtime scope ensures that Servlet API is in the classpath for both
execution and testing. It is not in the compile classpath though.
Fixed code formatting rules and reformat
Configures Failsave plugin for integration testing

Moves integration test configuration and code to separate file and
uses Maven Failsafe plugin to execute integration tests in verify phase.
Merge branch 'integration-testing'