Added a comment on the features that will not work on firefox

lms/djangoapps/courseware/features/login.feature

@@ -11,6 +11,7 @@ Feature: Login in as a registered user
     And I submit my credentials on the login form
     Then I should see the login error message "This account has not been activated"
 
+    #CHROME ONLY, firefox will not redirect properly
     Scenario: Login to an activated account
     Given I am an edX user
     And I am an activated user

lms/djangoapps/courseware/features/signup.feature

@@ -3,6 +3,7 @@ Feature: Sign in
   As a new user
   I want to signup for a student account
 
+  #CHROME ONLY, firefox will not redirect properly
   Scenario: Sign up from the homepage
     Given I visit the homepage
     When I click the link with the text "Register Now"