Update version to 0.7.3

- Update Dependencies
- Switch to "check-internet-connected" module for checking if user is online/offline
- Show message box when error occurs on RPC connection
- Update LICENSE and copyright
- Update useragents

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ms-office-electron",
-  "version": "0.7.2",
+  "version": "0.7.3",
   "description": "An Unofficial Microsoft Office Online Desktop Client. Free of Cost.",
   "main": "main.js",
   "repository": {