Remove unnecessary test in user sessions test (#642)

Author: arpit-jn

spec/lib/auth0/api/v2/users_spec.rb

@@ -823,10 +823,6 @@
   end
 
   context '.user_sessions' do
-    it 'is expected to respond to user_sessions' do
-      expect(@instance).to respond_to :user_authentication_method
-    end
-
     it 'is expected to respond to user_sessions' do
       expect(@instance).to respond_to :user_sessions
     end