Test all examples in dev server and create page screenshots (snapshot testing) (#664)

* Fix Astroturf example

* Revert back tests for Astroturf example

* Test all examples in dev server and create page screenshots (snapshot testing)

* Run examples tests in sequential way to avoid excessive load

* Delay logo animation to avoid different results with snapshot testing

* Fix issue with infinity tests

* Increase failure threshold for snapshot tests

Author: artembatura