Merge branch 'master' of https://github.com/griddynamics/jagger into ListenersInvoke
Create InvocationListener
Merge branch 'master' of https://github.com/griddynamics/jagger into ListenersInvoke
Add listener-invocation-not-null-response element. Add unit tests
Merge branch 'master' of https://github.com/griddynamics/jagger into ListenersInvoke
Call validator before invocationListeners
Create flush-collector
Add some comments
Merge griddynamics/master
Merge pull request #391 from kgribov/ListenersInvoke

JFG-578 Create invocation listener