Add citation info file

CITATION

+If you want to quote this software, you can use the following bibtex snippet:
+
+@Misc{rwthmindstormsev3toolbox,
+  author       = {Atorf, L. and Sondermann, B. and Stadtmann, T. and Rossmann, J.},
+  title        = {RWTH - Mindstorms EV3 Toolbox},
+  year         = {2018},
+  version      = {1.0},
+  organization = {Institute for Man-Machine Interaction, RWTH Aachen University},
+  url          = {https://git.rwth-aachen.de/mindstorms/ev3-toolbox-matlab}
+}
\ No newline at end of file