This patch will re-order the if statements when checking what operating system the user is running. This is useful for people that already have a `notify-send` binary in their $PATH but are running OSX. An example of such requirements is anyone running `vagrant-notify` is required to have a `notify-send` binary on their $PATH. See [link](https://github.com/fgrehm/vagrant-notify#os-x).
…SX comand line utility. Closes #2562