Make CfAPI easy to set up for other groups

[ondrae]

Description

We've started getting requests for the CfAPI to be used by other groups.

• Public Media Stations - https://github.com/melodykramer/publicmedia#repos by @melodykramer
• Regional Planning Agencies - https://github.com/buckleytom/RegionalPlanners by @buckleytom

We should start making it easy for others to set it up themselves.

Tasks

• Add a guide on setting up to the current installation instructions.
• Make a template organization information sheet for people to copy.
• Move the org_source.csv to be an environmental variable.
• Add info to the deployment section about adding python run_update.py to the Heroku Scheduler addon.
• Can they just fork the Heroku app somehow?
• Also point people to new guides on how to set up the projects powered by the CfAPI with their new version.

[ondrae]

We've got examples of a publicmedia-cfapi up:
http://publicmedia-cfapi.herokuapp.com/api/
http://publicmedia-website.herokuapp.com/brigade/
https://publicmedia-issues.herokuapp.com/geeks/civicissues/widget

[tbuckl]

thanks @ondrae