Keyword argument fix

Author: JonasJasas

examples/alternative_converter.rb

@@ -12,7 +12,7 @@
 upload_io = ConvertApi::UploadIO.new(File.open('files/test.docx'))
 
 saved_files = ConvertApi
-  .convert('pdf', File: upload_io, converter: 'openofficetopdf')
+  .convert('pdf', {File: upload_io, converter: 'openofficetopdf'})
   .save_files(Dir.tmpdir)
 
 puts "The PDF saved to: #{saved_files}"