Encrypt secrets before storing in redis

[CasperWA]

          This makes sense. Essentially what we need is to hash/encrypt the secrets before storing in redis. That should solve it. The strategies can then get some interface to decrypting the secrets they may need. Or it's done from the service before invoking the strategies. Not _very_ important, but it should circumvent this issue.

However that's something for another day and another PR.

Originally posted by @CasperWA in #189 (comment)

See also the comment of @MBueschelberger immediately prior to this linked comment.