Update rosinstall to point at frc_control melodic-devel

[matthew-reynolds]

Pull Request

Contribution Checklist

• [x] I have read the contributing guide.
• [x] I have referenced relevant issues.
• [x] I have labeled accordingly.
• [x] I have detailed my changes as much as possible.

Change Checklist

• [ ] I have added tests.
• [x] I have added necessary documentation.
• [ ] I have tested my changes on real hardware.

Fixes #53, and therefore unblocks #41

Note that once frc_control finishes updating to melodic (beyond just renaming the default branch), further changes will be required in uwreact_robot. In particular, the Travis CI config will need to specify Melodic rather than Kinetic, otherwise we will mismatch with frc_control and the build will fail.

[matthew-reynolds]

@michaelwm please merge this ASAP. Once this lands, #41 will be ready to be merged as well, feel free to rebase it off of master and merge.

[matthew-reynolds]

Additional future changes, described above, tracked in #55