Plan to upgrade to InaSAFE v4

[lucernae]

We are planning to upgrade inasafe-realtime functionality to use InaSAFE v4.
To be able to do that, we list our upgrade plan and milestone point:

• Create develop branch and use it for develop (branched from master), then later after we release, update master branch
• We use InaSAFE v4 as dependency. To do this, list out dependencies for us to be able to use InaSAFE. The easiest one is to use requirements.txt from pip using github as source (to tagged branch). Then create a sample Dockerfile so it can be clear of verbose what the dependency is (QGIS LTR, osgeo package, celery etc). We can take the Dockerfile from our docker-geosafe.
• Decide a folder structure. I propose this one (not really fixed if there is a better suggestion):
  • docs (for documentation related)
  • inasafe (will be filled with our wrapper for headless and realtime package)
    • headless
    • realtime
• Create travis unittest. Uses docker container
• List all possible function for InaSAFE command line tool that needs to be upgraded or deprecated. Write unittest.
• List all possible function for Headless tasks that needs to be upgraded or added. Write celery unittest.
• List all possible function for Realtime tasks that needs to be upgraded or added. Write celery unittest.

Please, create child issue for relevant step, so we know the progress.
Will add more if comes to mind.

[gubuntu]

@lucernae please review and comment

and this should align with kartoza/geosafe#50 and seamless platform planning