TEST: added skips to make the tests more readable
PEP 8
Removed prints and del
TEST: Removed all the prints from test_optimize
Merge pull request #482 from Garyfallidis/fix_optimize_defaults_skip

TST: Skip tests for different versions of scipy for optimize.py
RF: deleted unused files
Merge pull request #485 from Garyfallidis/clean_eit

RF: deleted unused files
BF: fix travis version setting

Luckily Steven Silvester noticed that selecting Python versions for the
virtualenvs was not working : https://github.com/nipy/dipy/issues/487
Merge pull request #488 from matthew-brett/fix-travis-again

BF: fix travis version setting
NF: Find the closest vertex on a sphere for an input vector.
BF + NF: Implement find_closest for Hemisphere.
Account for antipodal symmetry as appropriate for Sphere/Hemisphere.
TST: Demonstrate that this is scale-invariant.
PEP8: whitespace between functions.