Introduces party_fould and sets up environment variables in the
config/application.yml file. The commit contains also an example
for the application.yml and the description in the Readme file now
mentions that it needs to be renamed and configured to get started.
The file now also contains the secret token so it is no longer stored
exposed to the public inside of the github repository. #199 @kej can be
closed now but needs rollout to production.