tests: run Browswestack tests only on one platform
tests: run Browswestack tests only on one platform

denisahac/foundation-sites,denisahac/foundation-sites,denisahac/foundation-sites,zurb/foundation-sites,zurb/foundation,DaSchTour/foundation-sites,zurb/foundation,zurb/foundation-sites,abdullahsalem/foundation-sites,zurb/foundation,zurb/foundation-sites,DaSchTour/foundation-sites,abdullahsalem/foundation-sites,abdullahsalem/foundation-sites