Missing State.h file

[an-ku-95]

Include for the State.h file given in the definitions.hpp file (~/fssim_gazebo_plugins/gazebo_race_car_model/include/definitions.hpp). The state.h file missing from fssim_common.

[dprossel]

I have encountered the same problem. This error most likely occurs, when the cpp header files are not generated before the gazebo_race_car_model is built. This should be fixed by building fssim_common manually before everything else or adding an explicit dependency to those headers in the CMakeLists.txt as in #10