Slate required check failed because of a MarkdownExample update

Instead of displaying `*required*` a recent PR started showing a
required column that displayed true/false. This broke the slate display
which is text. Instead of altering the parameters hash return a new one
that the slate example can revert.

lib/rspec_api_documentation/views/markdown_example.rb

@@ -9,8 +9,10 @@ def initialize(example, configuration)
       end
 
       def parameters
-        super.each do |parameter|
-          parameter[:required] = parameter[:required] ? 'true' : 'false'
+        super.map do |parameter|
+          parameter.merge({
+            :required => parameter[:required] ? 'true' : 'false',
+          })
         end
       end
 

lib/rspec_api_documentation/views/slate_example.rb

@@ -5,6 +5,14 @@ def initialize(example, configuration)
         super
         self.template_name = "rspec_api_documentation/slate_example"
       end
+
+      def parameters
+        super.map do |parameter|
+          parameter.merge({
+            :required => parameter[:required] == 'true' ? true : false,
+          })
+        end
+      end
     end
   end
 end