v1.6.4/version bump

- hide/show button
- popup redesign
- start of tutorial

app/public/manifest.json

@@ -1,7 +1,7 @@
 {
   "name": "Watch Party",
   "short_name": "WP",
-  "version": "1.6.3",
+  "version": "1.6.4",
   "description": "Watch streamed content together.",
   "background": {
     "page": "background.html"
@@ -21,7 +21,7 @@
     "https://play.google.com/movies/*",
     "https://*.crunchyroll.com/*"
   ],
-  "content_security_policy": "script-src 'self' https://www.gstatic.com/ https://*.firebaseio.com https://www.googleapis.com; object-src 'self'",
+  "content_security_policy": "script-src 'self' https://unpkg.com/ https://www.gstatic.com/ https://*.firebaseio.com https://www.googleapis.com; object-src 'self'",
   "content_scripts": [
     {
       "matches": [