ROS2

[pascalau]

This PR allows to build the package ros_vrpn in ROS2. This PR has been tested on my side against rolling but it should build against all recent ROS2 releases.

Requirements

• A ROS2 base install
• Colcon
• Colconized vrpn library (vrpn_vendor ros2 branch)

$ mkdir -p ros2_ws/src && cd ros2_ws
# apt install ros-rolling-ros-base ros-dev-tools # ROS repository has to be added beforehand
$ source source /opt/ros/rolling/setup.bash
$ cd src && git clone https://github.com/pascalau/vrpn_catkin.git -b ros2 && cd ..
$ cd src && git clone https://github.com/pascalau/ros_vrpn_client.git -b ros2 && cd ..
$ colcon build --symlink-install

Notable changes:

• Moved from ROS1 to ROS2
• Renamed Package to avoid naming collisions for cmake targets
• Added Linting tests
• Currently the folder test is not considered in the CMakeLists.txt file
• Dropped glog dependency since it was previously only used to check for null pointers. Equivalent functionality has been implemented with rclutils.

[rikba]

Also closes #61

[pascalau]

I was able to also add the previouly commented Unittests in the test folder.

[pascalau]

@clanegge I fixed the observed issue with the timestamps today. The issue was a new behaviour of the .seconds() function as well as numerical issues when calculating only with seconds() precision and not nanoseconds()