add revokeaccessToken, start/stopSilentRenew to TS

Author: brockallen

index.d.ts

@@ -162,6 +162,11 @@ export class UserManager extends OidcClient {
 
   querySessionStatus(args?: any): Promise<any>;
 
+  revokeAccessToken(): Promise<void>;
+
+  startSilentRenew(): void;
+  stopSilentRenew(): void;
+  
   events: UserManagerEvents;
 }