Respect auth set in upstream host uri

[jebentier]

Description:

Some private gem repos like Gemfury use Basic Auth with just an api key rather than a username and password (ex. https://<api_key>@gem.fury.io/<repo>). Setting up upstream mirroring for this case should work as described in #247, but because Faraday does not respect Basic Authentication being passed in the URL unless its of the user:pass format, some additional logic was needed to support this use case.

---

Tasks:

• Describe the problem / feature
• Write tests

I will abide by the code of conduct.

[olleolleolle]

Awesome addition!

[olleolleolle]

spec/gemstash/http_client_spec.rb:25:12: C: Style/StringLiterals: Prefer double-quoted strings unless you need single quotes to avoid extra backslashes for escaping.
  describe '#for' do
           ^^^^^^
spec/gemstash/http_client_spec.rb:26:13: C: Style/StringLiterals: Prefer double-quoted strings unless you need single quotes to avoid extra backslashes for escaping.
    context 'when user:pass auth is in the upstream url' do
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
spec/gemstash/http_client_spec.rb:32:13: C: Style/StringLiterals: Prefer double-quoted strings unless you need single quotes to avoid extra backslashes for escaping.
    context 'when api_key auth is in the upstream url' do
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
spec/gemstash/http_client_spec.rb:38:13: C: Style/StringLiterals: Prefer double-quoted strings unless you need single quotes to avoid extra backslashes for escaping.
    context 'when no auth is included in the upstream url' do
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[jebentier]

@olleolleolle Thank you for getting the test run done, I've gone ahead and fixed up the linter errors.

[olleolleolle]

I noted that the JRuby 9.2 build had failures from having a too-old RubyGems preinstalled: now we updated, and we went from "erroring the build" to "one test failure".

[olleolleolle]

@jebentier This is now merged!