Add required types to Functions SDK (#465)

* add necessary types back into dependencies

* remove from devdeps

* add changelog

Author: thechenky

changelog.txt

@@ -0,0 +1 @@
+* Includes required types for functions SDK.

package.json

@@ -29,6 +29,10 @@
     "test": "mocha -r ts-node/register ./spec/index.spec.ts"
   },
   "dependencies": {
+    "@types/cors": "^2.8.5",
+    "@types/express": "^4.11.1",
+    "@types/jsonwebtoken": "^8.3.2",
+    "@types/lodash": "^4.14.133",
     "cors": "^2.8.4",
     "express": "^4.17.1",
     "jsonwebtoken": "^8.3.2",
@@ -37,10 +41,6 @@
   "devDependencies": {
     "@types/chai": "^4.1.7",
     "@types/chai-as-promised": "^7.1.0",
-    "@types/cors": "^2.8.5",
-    "@types/express": "^4.11.1",
-    "@types/jsonwebtoken": "^8.3.2",
-    "@types/lodash": "^4.14.133",
     "@types/mocha": "^5.2.7",
     "@types/mock-require": "^2.0.0",
     "@types/nock": "^10.0.2",