More robust paths

Author: thalassemia

setup.py

@@ -26,9 +26,9 @@
 cython_extensions = [
     Extension('stochastic_arrow.arrowhead',
               sources=[
-                  'stochastic_arrow/mersenne.c',
-                  'stochastic_arrow/obsidian.c',
-                  'stochastic_arrow/arrowhead'+ext,],
+                  os.path.join(arrow_dir, 'mersenne.c'),
+                  os.path.join(arrow_dir, 'obsidian.c'),
+                  os.path.join(arrow_dir, '/arrowhead'+ext),],
               include_dirs=[arrow_dir, np.get_include()],
               define_macros=[('NPY_NO_DEPRECATED_API', 'NPY_1_7_API_VERSION')],
               )]