Add failing unit test.

test/python_unit/CMakeLists.txt

 SET(${PROJECT_NAME}_PYTHON_TESTS
   geometric_shapes
+  api
   )
 
 FOREACH(TEST ${${PROJECT_NAME}_PYTHON_TESTS})

test/python_unit/api.py

+import unittest
+from test_case import TestCase
+import hppfcl
+hppfcl.switchToNumpyArray()
+import numpy as np
+
+class TestMainAPI(TestCase):
+
+    def test_collision(self):
+        capsule = hppfcl.Capsule(1.,2.)
+        M1 = hppfcl.Transform3f()
+        M2 = hppfcl.Transform3f(np.eye(3),np.array([3, 0, 0]))
+
+        req=hppfcl.CollisionRequest()
+        res=hppfcl.CollisionResult()
+
+        self.assertTrue(not hppfcl.collide(capsule, M1, capsule, M2, req, res))
+
+    def test_distance(self):
+        capsule = hppfcl.Capsule(1.,2.)
+        M1 = hppfcl.Transform3f()
+        M2 = hppfcl.Transform3f(np.eye(3),np.array([3, 0, 0]))
+
+        req=hppfcl.DistanceRequest()
+        res=hppfcl.DistanceResult()
+
+        self.assertTrue(hppfcl.distance(capsule, M1, capsule, M2, req, res) > 0)
+
+if __name__ == '__main__':
+    unittest.main()