Remove use of stubs in tests.

spec/controllers/omniauth_callbacks_controller_spec.rb

@@ -4,20 +4,21 @@ describe Users::OmniauthCallbacksController do
 
   context ".find_authenticator" do
     it "fails if a provider is disabled" do
-      SiteSetting.stubs("enable_twitter_logins?").returns(false)
-      expect(lambda {
+      SiteSetting.enable_twitter_logins = false
+
+      expect {
         Users::OmniauthCallbacksController.find_authenticator("twitter")
-      }).to raise_error(Discourse::InvalidAccess)
+      }.to raise_error(Discourse::InvalidAccess)
     end
 
     it "fails for unknown" do
-      expect(lambda {
+      expect {
         Users::OmniauthCallbacksController.find_authenticator("twitter1")
-      }).to raise_error(Discourse::InvalidAccess)
+      }.to raise_error(Discourse::InvalidAccess)
     end
 
     it "finds an authenticator when enabled" do
-      SiteSetting.stubs("enable_twitter_logins?").returns(true)
+      SiteSetting.enable_twitter_logins = true
       expect(Users::OmniauthCallbacksController.find_authenticator("twitter")).not_to eq(nil)
     end
   end