CB-7978 Fixed launching chrome in Linux

- Fixed launching chrome in linux. It either launches chrome or google-chrome processes
- Reads config.xml looking for the source file to be used at the lauching of the browser. This will work for Linux, Windows and MacOs
I get an error that dir is already created if I run this twice.  Also, this call is async so is dangerous as is.

Probably you want to use `shelljs` instead: `shelljs.mkdir('-p', tmpDir).