fix(e2e): add index-nocache.html to run e2e tests without cache

using appcache while running e2e tests was causing the following
problems:
- Safari would occasionally reload the app (as a result of the appcache
  refresh) during the angular.validator.asychronous test, which would
  result in test failure and false positivy.
- Firefox6 would run the tests very slowly, disabling the cache resolved
  the latency issues
- Sometimes tests would run with stale code pulled from cache, which
  would result in flaky tests.