fix: Proper type definition for returned callback

Author: muratcorlu

package-lock.json

@@ -21,7 +21,7 @@
   "homepage": "https://github.com/muratcorlu/lambda-expressless#readme",
   "devDependencies": {
     "@types/accepts": "^1.3.5",
-    "@types/aws-lambda": "^8.10.33",
+    "@types/aws-lambda": "^8.10.40",
     "@types/connect": "^3.4.33",
     "body-parser": "^1.19.0",
     "jest": "^24.9.0",

package.json

@@ -1,8 +1,11 @@
 import { Request } from './request';
 import { Response } from './response';
-import { APIGatewayProxyHandler } from 'aws-lambda';
+import { APIGatewayProxyEvent, Context, APIGatewayProxyResult } from 'aws-lambda';
 import { NextFunction, NextHandleFunction } from "connect";
 
+export interface APIGatewayProxyHandler {
+  (event: APIGatewayProxyEvent, context: Context): Promise<APIGatewayProxyResult>
+}
 
 export interface Middleware extends NextHandleFunction {
     (request: Request, response: Response, next: NextFunction): void