Merge pull request #627 from ryu39/feature/fix_name_error_mime_js_in_…

…rails_510_beta

Fix NameError: uninitialized constant Mime::JS in Rails 5.1.0 beta

lib/wicked_pdf/wicked_pdf_helper.rb

@@ -23,8 +23,9 @@ def wicked_pdf_image_tag(img, options = {})
 
     def wicked_pdf_javascript_src_tag(jsfile, options = {})
       jsfile = WickedPdfHelper.add_extension(jsfile, 'js')
+      type = ::Mime.respond_to?(:[]) ? ::Mime[:js] : ::Mime::JS # ::Mime[:js] cannot be used in Rails 2.3.
       src = "file:///#{WickedPdfHelper.root_path.join('public', 'javascripts', jsfile)}"
-      content_tag('script', '', { 'type' => Mime::JS, 'src' => path_to_javascript(src) }.merge(options))
+      content_tag('script', '', { 'type' => type, 'src' => path_to_javascript(src) }.merge(options))
     end
 
     def wicked_pdf_javascript_include_tag(*sources)