extract: handle versioned formulae names
extract: handle versioned formulae names

Turn the output versioned formula from the form "name@version" to
"name-version", then following by appending the specific version
after it.

This solution ensures that separate extracted versions of a formulae
can exist alongside each other (e.g. 'python-2@2.7.17' and
'python-2@2.7.16').

EricFromCanada/brew,vitorgalvao/brew,konqui/brew,sjackman/homebrew,MikeMcQuaid/brew,reitermarkus/brew,vitorgalvao/brew,Homebrew/brew,EricFromCanada/brew,Homebrew/brew,sjackman/homebrew,JCount/brew,JCount/brew,Homebrew/brew,JCount/brew,mahori/brew,vitorgalvao/brew,claui/brew,sjackman/homebrew,reitermarkus/brew,MikeMcQuaid/brew,Homebrew/brew,EricFromCanada/brew,MikeMcQuaid/brew,reitermarkus/brew,mahori/brew,claui/brew,nandub/brew,konqui/brew,nandub/brew,mahori/brew,EricFromCanada/brew,vitorgalvao/brew,mahori/brew,claui/brew,JCount/brew,reitermarkus/brew,konqui/brew,claui/brew,konqui/brew,MikeMcQuaid/brew,sjackman/homebrew,nandub/brew,nandub/brew