StackExchange's blackbox[0] has solved this problem for me.

Alternatives:

  * https://github.com/AGWA/git-crypt 
  * https://github.com/shadowhand/git-encrypt
  * http://docs.ansible.com/ansible/playbooks_vault.html
  * https://github.com/elasticdog/transcrypt
  * http://www.passwordstore.org/

[0]: https://github.com/StackExchange/blackbox