Fix a typo

features/step_definitions/s3_steps.rb

 When /^I attach the file "([^"]*)" to "([^"]*)" on S3$/ do |file_path, field|
 When /^I attach the file "([^"]*)" to "([^"]*)" on S3$/ do |file_path, field|
-  definition = Paperclip::Tasks::Attachments.defintions_for(User)[field.downcase.to_sym]
+  definition = Paperclip::Tasks::Attachments.definitions_for(User)[field.downcase.to_sym]
   path = "https://paperclip.s3.amazonaws.com#{definition[:path]}"
   path = "https://paperclip.s3.amazonaws.com#{definition[:path]}"
   path.gsub!(':filename', File.basename(file_path))
   path.gsub!(':filename', File.basename(file_path))
   path.gsub!(/:([^\/\.]+)/) do |match|
   path.gsub!(/:([^\/\.]+)/) do |match|