added test for admin inviter

spec/controllers/admins_controller_spec.rb

@@ -102,9 +102,14 @@ describe AdminsController do
 
       it 'succeeds' do
         get :admin_inviter, :identifier => 'bob@moms.com'
-        response.should be_ok
+        response.should be_redirect
       end
 
+      it 'does not die if you do it twice' do
+        get :admin_inviter, :identifier => 'bob@moms.com'
+        get :admin_inviter, :identifier => 'bob@moms.com'
+        response.should be_redirect
+      end
       it 'invites a new user' do
         Invitation.should_receive(:create_invitee).with(:service => 'email', :identifier => 'bob@moms.com')
         get :admin_inviter, :identifier => 'bob@moms.com'