WebDriverHelper should create the screenshot parent directory

Change-Id: I1aad680de524f2d39cc4f81db477b91e555958cd
Reviewed-on: https://pirx.atteo.com/gerrit/584
Tested-by: Mr. Jenkins
Reviewed-by: Sławek Piotrowski <sentinel@atteo.com>
Refactorings of running tests multiple times

Change-Id: I750fdeb45fd352f0b113bdca42d6f6b6c3bdf9ce
Reviewed-on: https://pirx.atteo.com/gerrit/586
Tested-by: Mr. Jenkins
Reviewed-by: Sławek Piotrowski <sentinel@atteo.com>