Fix typos

railties/CHANGELOG.md

@@ -6,7 +6,7 @@
         Rails.application.message_verifier.verify(message)
         # => 'my sensible data'
 
-    It is recommended not not use the same verifier for different things, so you can get different
+    It is recommended not to use the same verifier for different things, so you can get different
     verifiers passing the name argument.
 
         message = Rails.application.message_verifier('cookies').generate('my sensible cookie data')

railties/lib/rails/application.rb

@@ -160,9 +160,9 @@ def key_generator
       end
     end
 
-    # Return a message verifier object.
+    # Returns a message verifier object.
     #
-    # This verify can be used to generate and verify signed messages in the application.
+    # This verifier can be used to generate and verify signed messages in the application.
     #
     # It is recommended not to use the same verifier for different things, so you can get different
     # verifiers passing the +verifier_name+ argument.