The current catkin requires catkin_pkg >= 0.1.12 as indicated in
https://github.com/ros/catkin/blob/groovy-devel/package.xml

.
See discussion in #99.

lb: minor tweaking and commit message rewording

Signed-off-by: Víctor Mayoral Vilches <v.mayoralv@gmail.com>
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@oss.bmw-carit.de>