Update README.md

README.md

 # ospi
 This library contains scripts for working with OpenSim files and pinocchio software. 
+
+## Required Dependencies:
+- Python 2.7, Numpy
+
+## Extra Dependencies:
+- Pinocchio: library for rigid multi-body dynamics. Can be download from here: http://stack-of-tasks.github.io/pinocchio/
+If you want to visualize your pinocchio model:
+- Gepetto-viewer: A graphical interface for pinocchio. Can be downloaded from here:
+    https://github.com/humanoid-path-planner/gepetto-viewer.git
+- Gepetto-viewer-corba: CORBA server/client for the Graphical Interface of Pinocchio. Can be downloaded from here:
+    https://github.com/humanoid-path-planner/gepetto-viewer-corba.git
+    
+    
+## Installing
+```json
+   $ python setup.py --prefix='your install path'
+```