Retreive all issues and comments on new install event

[SimonLab]

To get an example of the request response run this command in a terminal: curl https://api.github.com/repos/dwyl/github-backup/issues

• [x] Detect a new installation event: check the value of the action key of the payload is created and the value of X-Github-Event in the header of the post request send by Github: X-Github-Event should have the value "installationEvent": https://developer.github.com/v3/activity/events/types/#installationevent
  • [x] Get instalation token: see #25

• [x] ref: #29 Using the installation token of the repository where the new installation has been added, send a request to the Github API to get all the issues: auth as installation https://developer.github.com/apps/building-github-apps/authentication-options-for-github-apps/#generating-a-private-key api request: https://developer.github.com/v3/issues/#list-issues-for-a-repository Similar to the way we get the list of repositories on dwylbot: https://github.com/dwyl/dwylbot/blob/91b65bc4c9e57ec935f503fd82e4c39b5cb76252/lib/dwylbot_web/controllers/github_api/http_client.ex#L28-L34 we can use HTTPoison module to send http requests and Poison.Parser module to parse the payload and convert it to a Map

  This means that we need to filter the response to only get the issues and exclude the PRs

  gettting the closed issues is a bit more complicated and we will need to send another API request: https://developer.github.com/v3/issues/events/

Questions: Github let you install an app on a specific repository or on all the repositories of a user profile or organisation:

When installed on all the repositories will the install event be sent to the server for each repositories or is there another type of event that we need to catch for this case?

[nelsonic]

@SimonLab this is good for MVP. We may need to ask users if they want a per-repo installation once we launch.

[SimonLab]

When the Github App is installed on all the repositories github will send the following values: header value of X-github-event: "installation_repositories" value of key "added" of the payload: "new_installation_repositories"

[nelsonic]

@SimonLab looks good. thanks.