Github mock page

iex> jwt_token = Github.Client.generate_jwt_token(app_id: 12345, private_key_filepath: "app.pem")

iex> github_client = %Github.Client{jwt_token: "jwt_token"}

iex> github_client |> Github.Apps.Installations.find!(67890)
%Github.Client.Response{
  status: 200,
  headers: [...],
  body: %{"id" => 12345, ...},
  ...
}

def github(conn, _params) do
  authorize_url = Github.Oauth2.Client.authorize_url!(
    config: [client_id: "client_id", client_secret: "client_secret"],
    scope: "user:email"
  )
  conn |> redirect(external: authorize_url)
end

def github_callback(conn, %{"code" => code}) do
  access_token = Github.Oauth2.Client.access_token!(
    config: [client_id: "client_id", client_secret: "client_secret"],
    params: [code: code]
  )

  github_client = %Github.Client{access_token: access_token}

  %{"login" => login} = github_client |> Github.Users.find!() |> Map.fetch!(:body)
  [%{"email" => email} | _] = github_client |> Github.Users.Emails.list!() |> Map.fetch!(:body)
  ...
end