update tests to unittest2 (or unittest py2.7)

surf/test/test_edge.py

@@ -0,0 +1,26 @@
+import json
+import os
+import unittest
+
+from surf.geometry import Vertex, PolygonMesh
+
+
+class TestEdge(unittest.TestCase):
+
+    def setUp(self):
+        path, file_name = os.path.split(__file__)
+        self.samples_dir = os.path.join(path, os.pardir, os.pardir,
+                'blender', 'samples')
+        self.cube_file_name = os.path.join(self.samples_dir, 'cube.json')
+        with open(self.cube_file_name, 'r') as cube_file:
+            cube_json = json.load(cube_file)
+            self.cube = PolygonMesh(**cube_json)
+
+    def test_centroid(self):
+        e = self.cube.edges[0]
+        v = self.cube.centroid(e)
+        self.assertEqual(v, Vertex(-1, 0, 1))
+
+
+if __name__ == '__main__':
+    unittest.main(verbosity=3)