💥 [BREAKING] enable TLS if api key specified

[THardy98]

What was changed

DWISOTT

1. Part of Assume TLS enabled if API key provided in SDKs features#687

2. How was this tested:
   internals/credentials_test.go

3. Any docs updates needed?
   Maybe

[cretz]

(leaving main review to Go SDK owners, just a couple of notes here)

[cretz]

When true, TLS will not be used

Reading the code here, this is not true, TLS will still be enable if the TLS field is set. IMO you should either 1) disallow both this being true and the TLS field being set (my preference), or 2) document that this being true means anything in the TLS field is ignored, and then respect that in code.

[THardy98]

Ah I should've tested this. Added validation to make it mutually exclusive + test

[cretz]

Might as well document to users that we do this where API key is set by users (i.e. in the Godoc on the NewAPIKey* functions)

[THardy98]

added a little line to the new api key methods noting the auto TLS behavior

[Quinn-With-Two-Ns]

I'll note there is another approach where you instead add a method to Credentials like defaultTLS() *tls.Config and then provide different Credentials implementations that enable or disable TLS by default, but what you have here is fine other then @cretz comments.

[THardy98]

I'll note there is another approach where you instead add a method to Credentials like defaultTLS() *tls.Config and then provide different Credentials implementations that enable or disable TLS by default, but what you have here is fine other then @cretz comments.

Added validation to make TLS/TLSDisabled mutually exclusive + a test

[cretz]

LGTM, but would want to wait for Go SDK owner(s) approval. No preference on approach @Quinn-With-Two-Ns said vs what's here (hopefully it's rarely/never used anyways, heh)