Question about running `heroku_dnsimple_cert` exe

[sethhorsley]

After adding the gem to the gemfile of a project and trying to run heroku_dnsimple_cert it cannot find the command.
After running installing it globaly with gem install heroku_dnsimple_cert it still doesn't find the command.

If you can point me in a good direction I could add the instructions to the readme.

@timurvafin not sure if you're still maintaining this the project but I would love to help keep this project running.