Initial version of WebSockets playground project to CI

Including default stage set, all forced to succeed and tests marked
as insignificant.

Task-number: QTQAINFRA-788
Change-Id: I243de8b09cce78f3ae0438e0addffb63da06e4f0
Reviewed-by: Kurt Pattyn <pattyn.kurt@gmail.com>
Reviewed-by: Tony Sarajärvi <tony.sarajarvi@digia.com>