Ensure the pipeline modifier is loaded before we try the function_exp…

…orted? call

lib/absinthe/schema.ex

@@ -365,6 +365,8 @@ defmodule Absinthe.Schema do
   def apply_modifiers(pipeline, schema, opts \\ []) do
     Enum.reduce(schema.__absinthe_pipeline_modifiers__(), pipeline, fn
       {module, function}, pipeline ->
+        Code.ensure_loaded!(module)
+
         cond do
           function_exported?(module, function, 1) ->
             apply(module, function, [pipeline])
@@ -377,6 +379,8 @@ defmodule Absinthe.Schema do
         end
 
       module, pipeline ->
+        Code.ensure_loaded!(module)
+
         cond do
           function_exported?(module, :pipeline, 1) ->
             module.pipeline(pipeline)