Add dotenv for development environment variables
Make GitHub organisation optional

This will let people try out the app without having to create a GitHub
organisation, if they don't already have one.
Merge pull request #41 from intercom/github_org_optional

Make GitHub organisation optional
Create Atom feed. Test latest updated
Compare with seconds precision
Merge pull request #43 from mmolina/incidents-atom-feed

Create incidents Atom feed
merging
merge