fix(typescript): auth() can resolve with GitHubAppAuthenticationWithExpiration

Author: gr2m

src/types.ts

@@ -105,7 +105,9 @@ export interface OAuthAppAuthInterface {
 }
 
 export interface GitHubAppAuthInterface {
-  (options?: GitHubAppAuthOptions): Promise<GitHubAppAuthentication>;
+  (options?: GitHubAppAuthOptions): Promise<
+    GitHubAppAuthentication | GitHubAppAuthenticationWithExpiration
+  >;
 
   hook(
     request: OctokitTypes.RequestInterface,
@@ -114,6 +116,8 @@ export interface GitHubAppAuthInterface {
   ): Promise<OctokitTypes.OctokitResponse<any>>;
 }
 
+// INTERNAL STATE
+
 export type OAuthAppState = {
   clientId: string;
   clientSecret: string;