Improve unittests for REST API push

[lucernae]

• fix timezone bug for shake
• fix ash time format for REST push

Needed for: https://github.com/inasafe/inasafe-django/pull/257

[lucernae]

This unittests needs to be rerun after merging fix in https://github.com/inasafe/inasafe/pull/4905

[codecov[bot]]

Codecov Report

Merging #194 into develop will decrease coverage by 0.21%. The diff coverage is 80.76%.

@@             Coverage Diff             @@
##           develop     #194      +/-   ##
===========================================
- Coverage    78.97%   78.76%   -0.22%     
===========================================
  Files           40       40              
  Lines         1308     1521     +213     
  Branches        73       94      +21     
===========================================
+ Hits          1033     1198     +165     
- Misses         228      265      +37     
- Partials        47       58      +11

Impacted Files	Coverage Δ
src/realtime/flood/notify_rest.py	50% <ø> (ø)	:arrow_up:
src/realtime/ash/ash_hazard.py	91.91% <100%> (ø)	:arrow_up:
src/realtime/ash/notify_rest.py	60.6% <100%> (-1.16%)	:arrow_down:
src/realtime/tasks/tests/test_celery_tasks.py	89.84% <100%> (ø)	:arrow_up:
src/realtime/flood/process_events.py	74.35% <100%> (ø)	:arrow_up:
src/realtime/flood/flood_hazard.py	91.66% <100%> (ø)	:arrow_up:
src/realtime/ash/tests/test_ash_hazard.py	84.46% <73.33%> (-8.98%)	:arrow_down:
src/realtime/flood/tests/test_flood_hazard.py	84.41% <77.27%> (-9.79%)	:arrow_down:
src/realtime/tests/mock_server.py	80.2% <80%> (-0.68%)	:arrow_down:
src/realtime/earthquake/tests/test_shake_hazard.py	87.27% <84.12%> (-4.89%)	:arrow_down:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 50a2e27...967a4bd. Read the comment docs.