title: How to deploy .sekrets.key to heroku when I don't check it in Git repo
body: <p>I use <a href="https://github.com/ahoward/sekrets" rel="nofollow noreferrer">Sekrets</a> gem to securely manage SendGrid credential and other sensitive keys. The credential is encrypted in <strong>config/sekrets.yml.enc</strong>, and to decrypt, <strong>.sekrets.key</strong> file is needed, but it's not added in the git repo.</p>
  
  <p>I'm curious how to deploy the <strong>.sekrets.key</strong> to heroku so that keys in <strong>config/sekrets.yml.enc</strong> can be read. </p>
  
  <p>Below are the errors when I deploy my learning Rails project to heroku.</p>
  
  <blockquote>
    <p><code>$ git push heroku master</code></p>
  </blockquote>
  
  <pre><code>...
  remote:        Running: rake assets:precompile
  remote:        missing /tmp/build_671f2f0c0250a9bd91df5c10138a4aae/.sekrets.key
  remote:        rake aborted!
  remote:        NoMethodError: undefined method `sendgrid' for "{}\n":Map
  remote:        /tmp/build_671f2f0c0250a9bd91df5c10138a4aae/vendor/bundle/ruby/2.3.0/gems/map-6.6.0/lib/map.rb:652:in `method_missing'
  remote:        /tmp/build_671f2f0c0250a9bd91df5c10138a4aae/config/environment.rb:11:in `&lt;top (required)&gt;'
  remote:        /tmp/build_671f2f0c0250a9bd91df5c10138a4aae/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.4/lib/active_support/dependencies.rb:293:in `require
  remote:        /tmp/build_671f2f0c0250a9bd91df5c10138a4aae/vendor/bundle/ruby/2.3.0/gems/activesupport-5.0.4/lib/active_support/dependencies.rb:293:in `block in require'
  ...
  </code></pre>
  
  <p>Really appreciate your reply. Thanks.</p>