Using failsafe plugin for Integration tests

Rename current Integration test to match failsafe default naming pattern and
mismatch surefire default naming pattern.
Add default execution for failsafe plugin
Create source-jar and javadoc-jar only for release
Use pom properties for compiler source and target
Uses JenkinsRule for Integration tests

Integration tests used to need a real Jenkins instance running on port 8080
but this could go wrong in CI environnement and needed Jenkins a specific
configuration. With this changes, Integration Test now setup there environment
and use jenkins-client classes to interrogate the Jenkins fake instance

fixes RisingOak/jenkins-client#25
Request Crumb field and value before post requests

fixes RisingOak/jenkins-client#26
Fix validator as 3xx are no errors

Jenkins has an issue [1] about responding 302 when requesting to build a job.

[1]: https://issues.jenkins-ci.org/browse/JENKINS-18407
Merge pull request #27 from alecharp/features/jenkins-automatic-integration-test

Remove plateforme based integration testing
Added HttpResponseContentExtractor.