Fix typo in 'a implementation'

Author: josevalim

lib/elixir/lib/module/types/apply.ex

@@ -1743,7 +1743,7 @@ defmodule Module.Types.Apply do
              but the #{inspect(mod)} protocol was not yet implemented \
              for any type and therefore will always fail.
 
-             This message will disappear once you define a implementation. \
+             This message will disappear once you define an implementation. \
              If the protocol is part of a library, you may define a dummy \
              implementation for development/test.
              """, ""}

lib/elixir/test/elixir/module/types/integration_test.exs

@@ -530,7 +530,7 @@ defmodule Module.Types.IntegrationTest do
 
             but the NoImplProtocol protocol was not yet implemented for any type and therefore will always fail.
 
-            This message will disappear once you define a implementation. If the protocol is part of a library, you may define a dummy implementation for development/test.
+            This message will disappear once you define an implementation. If the protocol is part of a library, you may define a dummy implementation for development/test.
 
             type warning found at:
             │