Add Docker images to ros_industrial/docker

[Joseph Schornak]

Currently the Docker images used for CI are defined by Dockerfiles within the yak repo and hosted on my personal Docker Hub repo, which isn't a good long-term situation. It would be better to add the Dockerfiles to the ros_industrial/docker repo and host the images on the ROS-Industrial Docker Hub.

The Dockerfiles need to meet the following requirements (the existing ones should serve as sufficient examples):

• Represent the different supported OS distributions. Currently Ubuntu Xenial and Bionic, and will include Focal once #42 is resolved.
• For each distro, provide a separate image for each supported CUDA version. Currently this is CUDA 9.2 and 10.2. Right now this is done by basing the image off a Nvidia CUDA image (for example, using FROM nvidia/cuda:10.2-cudnn7-devel-ubuntu18.04).
• The Xenial images need to include PCL 1.8 built from source. The Canonical-provided PCL package is PCL 1.7 and Yak does not build correctly with this version. I think the process of building PCL from source takes too long for the image to be build on Docker Hub, so I've been building the affected images locally and pushing them up.
• Each image needs to have the appropriate ROS1 version for that distro, since the Industrial CI pipeline uses ROS and the downstream yak_ros package needs ROS anyway.