[soap] Apply @aleung's SoapMethod fix

soap/index.d.ts

@@ -10,6 +10,10 @@ import * as events from 'events';
 interface Security {
 }
 
+export interface SoapMethod {
+  (args: any, callback: (err: any, result: any) => void, options?: any, extraHeaders?: any): void;
+}
+
 export class WSSecurity implements Security {
     constructor(username: string, password: string, options?: any);
 }
@@ -34,7 +38,7 @@ export interface Client extends events.EventEmitter {
     setEndpoint(endpoint: string): void;
     setSOAPAction(action: string): void;
     setSecurity(s: Security): void;
-    [method: string]: (args: any, callback: (err: any, result: any) => void, options?: any, extraHeaders?: any) => void;
+    [method: string]: SoapMethod | Function;
 }
 
 export interface Server extends events.EventEmitter {

soap/soap-tests.ts

@@ -1,4 +1,3 @@
-
 import * as soap from 'soap';
 import * as events from 'events';
 import * as fs from "fs";
@@ -27,10 +26,10 @@ soap.createClient(url, wsdlOptions, function(err: any, client: soap.Client) {
     client.getHttpHeaders();
     client.getSoapHeaders();
     client.setSOAPAction('action');
-    client['create']({ name: 'value' }, function(err: any, result: any) {
+    (client['create'] as soap.SoapMethod)({ name: 'value' }, function(err: any, result: any) {
         // result is an object
     });
-    client['create']({ name: 'value' }, function(err: any, result: any) {
+    (client['create'] as soap.SoapMethod)({ name: 'value' }, function(err: any, result: any) {
         // result is an object
     }, {});
     client.on('request', function(obj: any) {