simplified tracking activity controlling, added state updates in Pause and Resume
fixed a typo in ChallengeControllerTest
Merge branch 'DA-316' into unstable

* DA-316:
  fixed a typo in ChallengeControllerTest
  simplified tracking activity controlling, added state updates in Pause and Resume
Merge branch 'unstable' of github.com:ChallengeEarth/drallo-app into unstable

# By rzaitov
# Via rzaitov
* 'unstable' of github.com:ChallengeEarth/drallo-app:
  <DA-312> set version