only prepend http:// to endpoint if no protocol was provided

[Crunch09]

Hey,
this addresses the fix mentioned in #174: Although the Toxiproxy HTTP API does not support HTTPS, it should not prepend http:// to the endpoint.

client.NewClient("https://example.com")
// Before: http://https//example.com
// After: https://example.com

I would love to write a test for this but endpoint is not an exported identifier so i'm not sure how to test this as this is basically the first Go code that i have ever written 🙂

fixes #174

[jpittis]

This is an improvement over the current code. Thanks for opening a PR!

Because Toxiproxy does not support HTTPS, it might be nice to fail fast with a clear error message when an https: protocol is provided.

IMO it would be appropriate to fail with a log.Fatal("the toxiproxy client does not support https") if an HTTPS protocol is provided.

[jpittis]

Generally it's better to create a regex via regexp.MustCompile() and then calling the MatchString method. This ensures we don't ignore a possible error in the regex.

[Crunch09]

@jpittis Thank you for the review! 👍 I updated the code to now fail when https:// is provided and removed the regexp again because i felt it didn't add much value then but thank you for letting me know about MustCompile! 💯

Before:

After:

[jpittis]

Thanks for the contribution! :)