Remove expects(:token).never assertion

The test already verifies correct behavior via WebMock:

    stub_request(:get, url).with(basic_auth: [...])

If set_auth_from_token! incorrectly runs, it overwrites the
Authorization header with "token ...", which won't match the
basic_auth expectation and WebMock rejects the request.

Originally added in 39f2d9e.

Author: schneems

test/git_hub_bub/valid_token_test.rb

@@ -12,10 +12,9 @@ def test_does_not_add_token_to_header
     VCR.turned_off do
       token = "foo"
       url = "https://api.github.com/applications/#{ENV["GITHUB_APP_ID"]}/tokens/#{token}"
+      # Add a basic auth header, will fail if `'Authorization'=>'token ...'` header is added by mistake
       stub_get = stub_request(:get, url).with(basic_auth: [ENV["GITHUB_APP_ID"], ENV["GITHUB_APP_SECRET"]])
 
-      GitHubBub::Request.any_instance.expects(:token).never
-
       GitHubBub::Request.set_before_callback do |request|
         if request.token?
           # Should be true for this call