Update README.md

[bkakilli]

Fix in the readme for possible missing system packages (eigen, flann) and several required ros packages.

[rdube]

@bkakilli thanks for your contribution! Are you sure that all these packages are required? Eg. why ros-kinetic-interactive-markers? Also I would assume that some such as ros-kinetic-tf comes with the default ros install.

Please allow me to leave this PR open until we release the new version (easier not to forget about this when we overwrite).

[bkakilli]

Hi @rdube . I specifically don't know where all these packages are used in the code but I installed segmatch onto our desktop and Jetson TX2 (ubuntu 16.04) and in both systems the catkin build process failed until I install those packages.

Also I would assume that some such as ros-kinetic-tf comes with the default ros install.

It must be true for full-ros install, but I had installed ros-kinetic-ros-base, which probably does not carry those robot related packages. A clause such as "desktop or full version of ros is recommended/required" may be enough in your new release, not to create confusion.

[rdube]

Great thanks for the input!