Allow user to specify TLS ciphers an min/max TLS version

[dinghram]

My company requires specific cipher suites and control over TLS version used for security.

Modifications

ClientOptions now has TLSCipherSuites, TLSMinVersion, and TLSMaxVersion. These are used when creating tls.Config objects.

Verifying this change

This change is a trivial rework / code cleanup without any test coverage, simple pass-along variables to tls.Config objects.

Does this pull request potentially affect one of the following parts:

If yes was chosen, please highlight the changes

• Dependencies (does it add or upgrade a dependency): (no)
• The public API: (yes)
• The schema: (don't know)
• The default values of configurations: (no)
• The wire protocol: (no)

Documentation

• Does this pull request introduce a new feature? (yes)
• If yes, how is the feature documented? (not documented)
• If a feature is not applicable for documentation, explain why? Simple pass-along features with comments.
• If a feature is not documented yet in this PR, please create a followup issue for adding the documentation

[michaeljmarshall]

LGTM