ENH: Fixed logging in nsls2/__init__.py
MNT: Move gridder into core from recip

It doesn't make sense for the gridder to be in recip as there's
is nothing actually unique to reciprocal space in the gridder.
It makes more sense for it to be in core.
MNT: Realized I didn't move the corresponding gridder tests

- Moved the gridder tests from test_recip.py to test_core.py
- Put the ctrans import back in to recip.py
ENH: First attempt at coveralls integration
BUG: ...stupid typo
MNT: Attempting coveralls.io with nosetests
ENH: Added coveralls badge
MNT: reset .travis to run 'run_tests.py'

- fixed run_tests.py to run nosetests with coverage just on the
  nsls2 package.
DOC : added api_changes file
ENH : added bin edges -> bin centers function

 - convince function + test
ENH : improved efficiency

as suggested by Li Li
Merge pull request #104 from tacaswell/bin_edges2centers

ENH : added bin edges -> bin centers function
Merge pull request #108 from ericdill/coveralls

ENH: First attempt at coveralls integration
MNT: Included new documentation requirement

- For vistrails autowrapping, we need to know the name of the
  return variables because those become the names of the output
  ports.
Merge pull request #113 from ericdill/doc

Doc : Vistrails documentation addition - require Return variable names
WIP : first pass at auto-circle finding

 - implement separated 1D correlation between rows/columns and
   it's mirror
 - find maximum in this correlation to estimate symmetry center for each
   slice
 - use Hough transform logic to vote on location of symmetry plane for image
BUG/TST : added tests for center finding

 - fixed bug related to square images
MNT: Added scikit-image to conda install of travis yaml file
BUG : return a tuple as the doc claims
ENH : change what _corr_ax1 returns

return the histograms rather than just the most likely
mirror plane location.