Merge pull request #446 from aoberoi/v2-App-handleError-private

Make App.handleError() private (v2)

src/App.ts

@@ -643,7 +643,7 @@ export default class App {
   /**
    * Global error handler. The final destination for all errors (hopefully).
    */
-  public handleError(error: Error): Promise<void> {
+  private handleError(error: Error): Promise<void> {
     return this.errorHandler(asCodedError(error));
   }