Fix for rich comparison and add test for vec3 file

As __cmp__ no longer in Python 3 need to use functools.total_ordering which is in 2.7 and 3.*
  https://docs.python.org/2/library/functools.html#functools.total_ordering
  https://docs.python.org/3/library/functools.html#functools.total_ordering
  Define __eq__ and __lt__ and others are created automatically

Add unittest style for file vec3.py
Add unittest as separate file
Revert to original verison of test file
Remove ordering and property dceorators

Use just __eq__ and __ne__ fro comparison
Remove property decorator
Add missing function brackets in length function
Update test in response
Remove runner code
Move to PEP8 naming

Change variables and functions to lower_case
Delete old unit test

remove unit test to be replaced with py.test style
Add more tests and put in class

Put all tests in class so can use marker for class
Add additional missing tests
Move existing tests into the named function
Merge pull request #26 from hashbangstudio/vec3-update

Fix Vec3 equality and length, and flesh out its tests