Reduce diagonal covariance values

[jacobperron]

I'm not sure if this is the most correct thing to do, but it resolves rendering issues in RViz.

Connects to #55

[OYTIS]

Hi @jacobperron,

not a review really, just noticed that it's a backport from your personal repo. Your fork looks more up-to-date than the version in this repo. Any plans to merge your work here and/or adding melodic version to ROS repos? Is it still unstable?

Thanks!

[jacobperron]

@OYTIS I was planning on releasing the create_autonomy packages under a different name for Melodic onward, and cutting the releases from my personal fork. The reason is to have semantically more meaningful names for the packages. Instead of ca_driver, ca_description, etc, we will have create_driver, create_description, etc. And the new metapackage is named create_robot. This is more in-line with ROS naming conventions for packages.

I will keep this repo alive as long as Kinetic. And then I'll consider merging the repositories: either archiving this one preferring my fork or renaming this repository and archiving my fork.