[Request]SSL Config Enhancement - versions and ciphers environmental variables

[wdhowe]

Please add the ability to pass environmental variables to set the SSL options for "versions" and "ciphers".

Being able to set things such as TLSv1.2 and eliminate 3DES ciphers is important in highly scrutinized security environments.

[michaelklishin]

See docker-library/docs#1011 for a way to set any configuration setting you want via RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS .

[tianon]

Indeed, and in 3.7, this should be even easier to configure via the newer configuration file format (see #197 for where that discussion is happening). 👍