warning: constant OpenSSL::Cipher::Cipher is deprecated

[lukemalinowski]

The fix is in a PR opened in February, but it looks like gibberish isn't very actively maintained so it has not been merged yet: mdp/gibberish#27

Additionally, the deprecation itself is purely an API level change per the following source. The deprecated class is identical to the new class with exception of the deprecation message being inserted:
https://github.com/ruby/openssl/blob/master/lib/openssl/cipher.rb

In all, Gibberish seems to be more of an issue than the usage of the Cipher::Cipher openssl class.

[yarick]

I would suggest to consider adding a note to that effect to Readme.md

[lukemalinowski]

Will do, also should mention that despite not being actively maintained, gibberish is relatively small and will likely be acceptable.