v0.11.0 / Firefox 78.0.1 release (#706)

* Update to FF 78_0_1
* npm updates
* Repin python
* New version number.
* Make CHANGELOG a markdown file, so it renders nicely

Author: birdsarah

.codecov.yml

@@ -4,4 +4,4 @@ coverage:
     project:
       default:
         threshold: 2
-        target: 40%
+        target: 40%