Auto-update dependencies.

Author: dpebot

firestore/index.html

@@ -12,8 +12,8 @@
 
   <script>mocha.setup('bdd')</script>
 
-  <script src="https://www.gstatic.com/firebasejs/8.10.0/firebase.js"></script>
-  <script src="https://www.gstatic.com/firebasejs/8.10.0/firebase-firestore.js"></script>
+  <script src="https://www.gstatic.com/firebasejs/9.0.0/firebase.js"></script>
+  <script src="https://www.gstatic.com/firebasejs/9.0.0/firebase-firestore.js"></script>
   <script src="test.firestore.js"></script>
   <script src="test.solution-arrays.js"></script>
   <script src="test.solution-counters.js"></script>