Enable basic auth tests with domainless custom authenticator

[mconnew]

Fixes #1111

[roncain]

These tests are failing on *nix with the error:

MESSAGE:
Test Case: BasicAuthentication FAILED with the following errors: Basic echo test.Test variation:...\nBasicAuthentication_RoundTrips_Echo
Using address: 'https://wcfcoresrv2.cloudapp.net/WcfService4//BasicAuth.svc/https-basic'\nUnexpected exception was caught: System.ServiceModel.CommunicationException: An error occurred while sending the request. ---> System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.Http.CurlException: SSL peer certificate or SSH remote key was not OK
at System.Net.Http.CurlHandler.ThrowIfCURLEError(CURLcode error)
 at System.Net.Http.CurlHandler.MultiAgent.FinishRequest(StrongToWeakReference`1 easyWrapper, CURLcode messageResult)\n --- End of inner exception stack trace ---

The SSL_Available ConditionalFact was used for all tests that failed with this kind of exception in the past, pending deeper investigation of what is required for automated installation scripts.

[roncain]

Why did you remove this ConditionalFact? Do we know Basic_Authentication_Available is true for all platforms, both self-host and IIS-host?

[mconnew]

The the whole point of this change, it enables Basic authentication by using a custom authenticator on the server side so you don't need to use real credentials to test it. As there's no such thing as ambient credentials with Basic authentication, there's no need to have a test variant which uses a real domain.

[roncain]

@StephenBonikowsky is doing a massive sweep to "version-ize" the tests in PR #1366. I think it would be most efficient if we allowed his PR to be completed and then re-apply the changes in this PR. My own PeerTrust branch is also waiting for that PR to finish.

[mconnew]

@iamjasonp, do you know why this test is getting this exception: System.Net.Http.CurlException: Peer certificate cannot be authenticated with given CA certificates

[iamjasonp]

I wouldn't expect that to pass - root certs aren't installed on CI machines. I'm mildly surprised that Root_Certificate_Installed is evaluating to true.

[iamjasonp]

Ah, I see - note that CA certificates being used by cURL does not use the x509 stores. So while Root_Certificate_Installed is evaluating to true (because certs are being installed fine in the .NET x509 cert stores), https calls won't work because they depend on the system cert store.

[iamjasonp]

#1304 will help with getting these tests running in Helix/CI

[mconnew]

@dotnet-bot test all outerloop

[mconnew]

@dotnet-bot test all outerloop

[iamjasonp]

If the default platforms (Windows_NT, Ubuntu14.04, CentOS7.1, OSX) pass, don't worry about the remaining outerloop CI failures for the new platforms we turned on in CI

[mconnew]

Windows_NT Debug failure was unrelated so merging.