Change data path; Add test info in README

README now include information on how to run tests and where to run
them, i.e. run py.tests inside the tests/ folder. If py.test does not
run inside of test/ then the unit test will not find the data files.
Change test halfedge_vertices_...in_order vertices

Add test_test in order to print out progress in currect function.
Parse off vertices

Create Vertex type for the vertices. Need to parse faces and edges.