Fix request-promise compile error (#59)

package.json

@@ -230,7 +230,8 @@
         "@types/fs-extra": "^4.0.3",
         "@types/mocha": "^2.2.32",
         "@types/node": "^8.0.28",
-        "@types/request-promise": "^4.1.38",
+        "@types/request-promise": "4.1.38",
+        "@types/request": "2.0.7",
         "mocha": "^2.3.3",
         "tslint": "^5.7.0",
         "tslint-microsoft-contrib": "5.0.1",