Safely check COM port attributes (#37)
Safely check COM port attributes (#37)

Bug fix to check if the port product exists. This caused issues when
plugging in other USB COM devices, such as Arduinos who didn't have the
port.product attribute.

Squashed commit of the following:

commit 6247987a1aa9bc37ccff4efffe1e2c3572cc280b
Author: Elliot Berman <berman5@purdue.edu>
Date:   Wed May 31 21:20:34 2017 -0500

    Fix #36

purduesigbots/purdueros-cli,purduesigbots/pros-cli