Add CONTRIBUTORS file (#181)

* Add CONTRIBUTORS file

Containing all of those who have committed to the project.

Signed-off-by: Jacob Perron <jacob@openrobotics.org>

* Update contributors list based on new commits

Signed-off-by: Jacob Perron <jacob@openrobotics.org>

Author: jacobperron

CONTRIBUTORS

@@ -0,0 +1,14 @@
+Esteve Fernandez
+Ivan Paunovic, Ekumen
+Jacob Perron, Open Source Robotics Foundation, Inc.
+Duncan Calvert
+Martin Huber
+konczg
+qiao
+sung-goo-kim
+Niels Tiben
+jayhou
+konczg
+nielstiben
+pluris
+talregev