docs(limitTo): exclude the e2e test that fails on safari

Safari and doesn't like the minus key to be sent to it via Protractor.

Author: petebacondarwin

src/ng/filter/limitTo.js

@@ -50,7 +50,8 @@
          expect(limitedLetters.getText()).toEqual('Output letters: abc');
        });
 
-       it('should update the output when -3 is entered', function() {
+       // There is a bug in safari and protractor that doesn't like the minus key
+       xit('should update the output when -3 is entered', function() {
          numLimitInput.clear();
          numLimitInput.sendKeys('-3');
          letterLimitInput.clear();