Chapter 6 Lab, Docker-Machine install instructions out of date

I used the instructions from this page, and docker-machine installed fine and the rest of lab went fine.

https://docs.docker.com/machine/install-machine/

<span class="nv" style="box-sizing: border-box; color: rgb(0, 104, 139);">base</span><span class="o" style="box-sizing: border-box;">=</span>https://github.com/docker/machine/releases/download/v0.14.0 <span class="o" style="box-sizing: border-box;">&&</span>
<span class="gp" style="box-sizing: border-box; color: rgb(85, 85, 85);">  curl -L $</span>base/docker-machine-<span class="k" style="box-sizing: border-box; color: rgb(139, 0, 139);">$(</span>uname <span class="nt" style="box-sizing: border-box; color: rgb(139, 0, 139);">-s</span><span class="k" style="box-sizing: border-box; color: rgb(139, 0, 139);">)</span>-<span class="k" style="box-sizing: border-box; color: rgb(139, 0, 139);">$(</span>uname <span class="nt" style="box-sizing: border-box; color: rgb(139, 0, 139);">-m</span><span class="k" style="box-sizing: border-box; color: rgb(139, 0, 139);">)</span> <span class="o" style="box-sizing: border-box;">></span>/tmp/docker-machine <span class="o" style="box-sizing: border-box;">&&</span>
<span class="go" style="box-sizing: border-box; color: rgb(136, 136, 136);">  sudo install /tmp/docker-machine /usr/local/bin/docker-machine</span>