Add basic unit tests rules in PlayApplicationPlugin

- add test for 'createTestTasks' Rule

+review REVIEW-5263
test play app is running in common AbstractPlayAppIntegrationTest

- remove PlayRunIntegrationTest
- remove unused playNew resources
- remove unused method in PlayRun
- remove explicit log level setup (debug) in PlayApplicationRunner

TODO:
 - fix test on windows
 - fix CustomPlayApp sample to run correctly