Fix all the errors to get our tests green on Rails 5.1.

spec/components/cache_spec.rb

@@ -41,7 +41,7 @@ describe Cache do
     cache.delete("key")
     cache.delete("bla")
 
-    key = cache.namespaced_key("key")
+    key = cache.normalize_key("key")
 
     cache.fetch("key", expires_in: 1.minute) do
       "bob"
@@ -52,7 +52,7 @@ describe Cache do
     # we always expire withing a day
     cache.fetch("bla") { "hi" }
 
-    key = cache.namespaced_key("bla")
+    key = cache.normalize_key("bla")
     expect($redis.ttl(key)).to be_within(2.seconds).of(1.day)
   end