check the yarn globle modules if useYarn

Created by: guoyang007

'global-modules' can only get the global packages installed by npm: https://www.npmjs.com/package/global-modules

get the current global modues installed by yarn: https://github.com/yarnpkg/yarn/issues/2049#issuecomment-337870443

Since the global module dir is different with yarn and npm, we should check the corresponding global modules dir if use yarn.