Only install Vagrant plugin if the plugin is missing.

if command -v vagrant > /dev/null

then

	echo Installing Vagrant plugins >> /dev/stderr

	vagrant plugin install landrush || true

	vagrant plugin install vagrant-gatling-rsync || true

    for plugin in landrush vagrant-gatling-rsync

    do

        vagrant plugin list | grep -qw "$plugin" || vagrant plugin install "$plugin" || true

    done

fi