Fix and re-enable webpurify tests

[islemaster]

The WebPurify unit tests have been frequently failing on Circle CI lately.

While I explored changes to the WebPurify component recently, neither the source file, nor the test file, nor the VCR files have been touched since October.

VCR debug logging revealed the issue.

[VCR::Configuration] before_playback: replacing "<ENDPOINT>" with "https://region.api.cognitive.microsoft.com/contentmoderator"
[VCR::Configuration] before_playback: replacing "<API_KEY>" with "fakekey"
[VCR::Configuration] before_playback: replacing "<API_KEY>" with "mocksecret"

Ends up trying to match fakekey when it should be matching mocksecret:

[get http://api1.webpurify.com/services/rest/?api_key=fakekey&format=json&lang=en&method=webpurify.live.return&text=schei%C3%9Fe]

Meaning I actually broke the WebPurify tests by adding these Azure tests.

The root of the problem is that these VCR replacements share a global namespace, and there's a collision in the <API_KEY> replacement. I think these tests would pass if the random test ordering loaded the mocksecret replacement first.

The fix is to give the Azure tests a unique secret replacement, like <AZURE_API_KEY>, and regenerate those VCR files.

[davidsbailey]

Nice find, nice fix!