Update package description to specify OpenGL 3.3+

Author: einarf

setup.py

@@ -3,7 +3,7 @@
 setup(
     name="demosys-py",
     version="0.3.10",
-    description="Modern OpenGL 4.1+ Framework inspired by Django",
+    description="Modern OpenGL 3.3+ Framework inspired by Django",
     long_description=open('README.rst').read(),
     url="https://github.com/Contraz/demosys-py",
     author="Einar Forselv",