[osx] Fix "'xcodebuild' requires Xcode" error
[osx] Fix "'xcodebuild' requires Xcode" error

By default, the `xcode-select` developer directory points to
`/Library/Developer/CommandLineTools`, but since it doesn't
get (immediately?) updated to point to the appropriate directory
from within `Xcode.app` once `Xcode` is installed, the following
error will be raised when trying to install anything that require
the `Xcode` CLTs:

 " xcode-select: error: tool 'xcodebuild' requires Xcode, but
   active developer directory '/Library/Developer/CommandLineTools'
   is a command line tools instance. "

This commit fixes the issue described above by making the
`xcode-select` developer directory point to the appropriate
directory from within `Xcode.app` once Xcode is installed.

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Fix alrra/dotfiles#13
Ref alrra/dotfiles#13

wingy3181/dotfiles,zlot/dotfiles,girishramnani/dotfiles,AlbertoElias/dotfiles,newtonne/dotfiles,b-boogaard/dotfiles,pbrooks/dotfiles,zlot/dotfiles,EDiLD/dotfiles,christophermoura/dotfiles,mickael83/ubuntu-dotfiles,AlbertoElias/dotfiles,girishramnani/dotfiles,mickael83/ubuntu-dotfiles,newtonne/dotfiles,makabde/dotfiles,wingy3181/dotfiles,makabde/dotfiles,wingy3181/dotfiles,christophermoura/dotfiles,EDiLD/dotfiles,oddlord/dotfiles