Adopt tests to respect Raven context

spec/controllers/sessions_controller_spec.rb

@@ -154,7 +154,10 @@ describe SessionsController do
 
   describe 'DELETE #destroy' do
     let(:user) { double }
-    before(:each) { expect(controller).to receive(:current_user).at_least(:once).and_return(user) }
+    before(:each) {
+      allow(controller).to receive(:set_raven_context).and_return(nil)
+      expect(controller).to receive(:current_user).at_least(:once).and_return(user)
+    }
 
     context 'with an internal user' do
       before(:each) do
@@ -217,6 +220,8 @@ describe SessionsController do
   describe 'GET #new' do
     context 'when no user is logged in' do
       before(:each) do
+        allow(controller).to receive(:set_raven_context).and_return(nil)
+
         expect(controller).to receive(:current_user).and_return(nil)
         get :new
       end
@@ -227,6 +232,8 @@ describe SessionsController do
 
     context 'when a user is already logged in' do
       before(:each) do
+        allow(controller).to receive(:set_raven_context).and_return(nil)
+
         expect(controller).to receive(:current_user).and_return(FactoryBot.build(:teacher))
         get :new
       end