.ruby-env.yml.example in mailgun-ruby-1.2.12 vs .ruby-env.yml.example in mailgun-ruby-1.2.13

@@ -8,5 +8,6 @@
 # https://mailgun.com/app/dashboard (don't include <brackets>)
 # and rename to/save as: .ruby-env.yml
 MAILGUN_APIKEY : '<MAILGUN_APIKEY>'
 MAILGUN_PUB_APIKEY : '<MAILGUN_PUBLIC_APIKEY>'
 MAILGUN_TESTDOMAIN : '<MAILGUN_SANDBOX_DOMAIN>'
+