Stable ROS2 for OSR v1

Supports ROS2 Foxy, Galactic, Humble, assuming appropriate OS.

What's Changed

• Convert code base to ROS2 Foxy by @Achllle in #126
• Backport odometry to foxy-devel and other ROS2 related fixes by @Achllle in #132
• Fix default drive motor speed by @Achllle in #139
• Improve systemd service by @Achllle in #137
• Fix #151 by @Achllle in #153
• Update rpi.md by @KirillMcQ in #164

Full Changelog: v3.0.0...v4.0.0

First stable software release

This is our first "real" release of the project with a formal version. The idea is to do better version tracking going forward.

Key features:

• Pololu DC drive motors
• Actobotics planetary gear corner motors
• Servocity aluminum plates for top and bottom of body frame
• Traxxas wheels
• PCB revE
• RPi 3 or 4 supported
• Runs ROS1

Date	Hardware Version	Software Version
July 1, 2021	v3.0.0	v3.0.0

Open Source Rover V1 - Legacy

This is the software package to run the JPL Open Source Rover, tagged with the initial legacy release design of the rover.

https://github.com/nasa-jpl/open-source-rover/releases/tag/v1.0