Only run Saucelabs test with secure variables

This is intended to short circut PRs so that they don't get marked as
failed when they don't have access to the Sauce vars.
Merge pull request #189 from nschonni/shortcircut-pr-builds

Only run Sauce Labs test when secure environment variables are available
Fix the CI script

The [ function doesn't support "&&" (you need [[ for that).

Also added an echo statement to inform that no tests were run if no if
statements matched.
Change Ember.run.later to setTimeout in periodic actions

It seems that running Ember.run.later periodically can cause CPU usage
to increase over time. Such increase adds up to already increasing CPU
usage because of data amount growing.

This commit tries to mitigate the issue by using setTimeout instead