replace maven-invoker-plugin with hand crafted plugin integration tests

[jamesdbloom]

maven-invoker-plugin is not very reliable or straightforward to use and does not meet all the required use cases. In particular maven-invoker-plugin does not execute unit tests that are part of an integration-test maven project (even though it is supposed to be running mvn package).

To the simplest way to resolve this is to create a simple integration test that runs the sample project (including tests) and passes or fails based on the process return code and the presence of the log file. In addition if the test fails the console output should show the result of the maven execution.

[jamesdbloom]

not required as managed to configure maven-invoker-plugin to run unit tests