Add --rosdistro=kinetic tag since EOL (to README)

[Sridhar701Pitt]

Please update the README file in ICRA2020 and IROS2021
rosdep install --from-paths src -i -y
to
rosdep install --from-paths src -i -y --rosdistro=kinetic
since kinetic is now officially EOL and rosdep does not install kinetic packages by default