Bump README version

README.md

@@ -19,7 +19,7 @@ Add `:broadway_cloud_pub_sub` to the list of dependencies in `mix.exs`:
 ```elixir
 def deps do
   [
-    {:broadway_cloud_pub_sub, "~> 0.8.0"},
+    {:broadway_cloud_pub_sub, "~> 0.9.0"},
     {:goth, "~> 1.3"}
   ]
 end