Authenticating as an installation

  In order to authenticate to GitHub as an installation of your GitHub App, you must use the App Installation Token
  authentication mechanism. This can be achieved with by creating a <<<GitHub>>> instance like this:

+-----+
GitHub githubAuthAsInst = new GitHubBuilder()
                    .withAppInstallationToken(appInstallationToken.getToken())
                    .build();
+-----+

How do I create an App Installation Token?

  Assuming that you followed the {{{/githubappjwtauth.html} GitHub App Authentication via JWT token guide}} then you
  can create the App Installation Token like this:

+-----+
String jwtToken = createJWT("44435", 600000); //sdk-github-api-app-test
GitHub gitHubApp = new GitHubBuilder().withJwtToken(jwtToken).build();
GHAppInstallation appInstallation = gitHubApp.getApp().getInstallationById(111111); // Installation Id

Map<String, GHPermissionType> permissions = new HashMap<>();
permissions.put("pull_requests", GHPermissionType.WRITE);

GHAppInstallationToken appInstallationToken = appInstallation
                    .createToken(permissions)
                    .create();
+-----+
