Update README to reflect loss of scipy dependency

README.md

@@ -35,8 +35,8 @@ Requirements
 
   * PyQt 4.7+ or PySide
   * python 2.6, 2.7, or 3.x
-  * numpy, scipy
-  * For 3D graphics: pyopengl
+  * NumPy 
+  * For 3D graphics: pyopengl and qt-opengl
   * Known to run on Windows, Linux, and Mac.
 
 Support
@@ -53,6 +53,9 @@ Installation Methods
   * To install system-wide from source distribution:
         `$ python setup.py install`
   * For instalation packages, see the website (pyqtgraph.org)
+  * On debian-like systems, pyqtgraph requires the following packages:
+        python-numpy, python-qt4 | python-pyside
+        For 3D support: python-opengl, python-qt4-gl | python-pyside.qtopengl
 
 Documentation
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