Add setup.py install_requires

Author: ericPrince

README.md

@@ -2,6 +2,8 @@
 
 Pure python geometric constraint solver
 
+`import gcs`
+
 See `gcs/solve_elements.py` for a description of the
 mechanics behind this package. Essentially, gcs implements
 a constraint solver that breaks a problem into fully 

gcs/eqn_set_splitting_proto.py

@@ -1,4 +1,4 @@
-#note: these functions are not used, see equation_solving instead
+# note: these functions are not used, see equation_solving instead
 
 from blist import sortedlist
 

setup.py

@@ -6,4 +6,13 @@
     version='0.0.1',
     description='Geometric constraint solver',
     packages=find_packages(),
+    install_requires=[
+        'numpy',
+        'scipy',
+        'matplotlib',
+        'python-igraph',
+        'pycairo',
+        'blist',
+        'sortedcontainers',
+    ]
 )