Add webpack type definitions

package.json

@@ -64,6 +64,7 @@
     "@types/mocha": "^2.2.39",
     "@types/request-promise": "^4.1.42",
     "@types/sinon": "^4.3.1",
+    "@types/webpack": "^4.4.24",
     "awesome-typescript-loader": "^3.4.1",
     "chai": "^3.5.0",
     "glob": "^7.1.2",

webpack.config.ts

@@ -1,4 +1,6 @@
+// tslint:disable:no-object-literal-type-assertion
 import * as path from "path";
+import { Configuration } from "webpack";
 
 module.exports = {
     entry: "./src/index.ts",
@@ -33,4 +35,4 @@ module.exports = {
 
     // Because docx is now targetting web
     // target: 'node',
-};
+} as Configuration;