Bump version to 4.2.0 (#832)

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "code-push",
-  "version": "4.1.3",
+  "version": "4.2.0",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "code-push",
-  "version": "4.1.3",
+  "version": "4.2.0",
   "description": "Management SDK for the CodePush service",
   "main": "script/index.js",
   "types": "script/index.d.ts",