Windows platform support: Convert double backslash to single backslash
Windows platform support: Convert double backslash to single backslash

See #2550 and https://github.com/Codeception/Codeception/pull/2551#issuecomment-167756694
Vreasy/Codeception,Codeception/Codeception,TehJoE/Codeception,Naktibalda/Codeception,kt81/Codeception,orhan-swe/Codeception,pitpit/Codeception,Naktibalda/Codeception,TehJoE/Codeception,tiger-seo/Codeception,Codeception/base,sergeyklay/Codeception,Naktibalda/Codeception,orhan-swe/Codeception,Codeception/Codeception,sergeyklay/Codeception,Codeception/base,tasselchof/Codeception,tasselchof/Codeception,kt81/Codeception,janhenkgerritsen/Codeception,hubbyist/Codeception,tasselchof/Codeception,tiger-seo/Codeception,pitpit/Codeception,hubbyist/Codeception,janhenkgerritsen/Codeception,Codeception/base,Vreasy/Codeception