Merge tag 'sparks-3.0.1' into develop

3.0.1
Add upstart templates.
Implement `upstart` service configuration/management and make it the default. `supervisor` takes precedence only if installed.
upstart: try to start the task if restart failed. This happens either if the task was never started before, or if it crashed.
Fixes to the upstart templates. They are now fully working (deployed on {obi,worbi}.1flow.io).
bump version in __init__.py
Merge branch 'release/3.1'