Add tests for openid signup with every provider

The spec for omniauth doesn't test signup for every provider, and it
doesn't test if it has tests for all available providers
Also, we no longer use secrets

* Add model test to check if the omniauth providers have changed
* Test signup using every provider
* Replace secretswith environment variables

spec/features/omniauth_spec.rb

@@ -118,9 +118,35 @@ feature Openid do
     end
   end
 
+  shared_examples 'sign up with openid' do |provider|
+    scenario "has option to sign in with #{provider}" do
+      visit '/accounts/sign_up'
+      expect(page.has_content?('or sign in using')).to eq true
+      expect(page.has_link?("omniauth-#{provider}")).to eq true
+    end
+
+    scenario "sign up with #{provider}" do
+      expected_count_openid = Openid.count + 1
+      expected_count_user = User.count + 1
+      visit '/accounts/sign_up'
+
+      mock_auth_accounts
+      within('#openidlinks') do
+        click_link "omniauth-#{provider}"
+      end
+      expect(flash).to eq("user-#{provider}@example.com signed in successfully with #{provider}")
+      expect(Openid.count).to eq(expected_count_openid)
+      expect(User.count).to eq(expected_count_user)
+    end
+  end
+
   describe 'omniauth' do
     if User.omniauth_providers.present?
       it_behaves_like 'sign in with openid'
+
+      User.omniauth_providers.each do |provider|
+        it_behaves_like 'sign up with openid', provider
+      end
     end
   end
 end