Use stable module version

Using stable version of node modules. 
Using '*' or 'latest' in node modules version could cause unexpected results and could break your code.

app/package.json

@@ -27,15 +27,15 @@
     "InstantMessaging"
   ],
   "dependencies": {
-    "electron-is-dev": "*",
-    "electron-squirrel-startup":"*",
-    "configstore": "^2.0.0",
+    "electron-is-dev": "0.1.2",
+    "electron-squirrel-startup": "1.0.0",
+    "configstore": "2.1.0",
     "dialogs": "1.1.14",
-    "electron-debug": "^1.0.0",
-    "electron-localshortcut": "^0.6.1",
-    "node-json-db": "^0.7.2",
-    "request": "^2.74.0",
+    "electron-debug": "1.1.0",
+    "electron-localshortcut": "0.6.1",
+    "node-json-db": "0.7.3",
+    "request": "2.79.0",
     "electron-spellchecker": "0.7.0",
-    "wurl": "^2.1.0"
+    "wurl": "2.1.0"
   }
 }