My fix for issue #966
Moved code to where it belongs.
Somehow it got left in the old place, so the bug was still occurring.
Added test for add_row() failures.
Modified the spherical distances with NumPy

The spherical distances functions are now NumPy dependent. They no
longer depend on Python's math library.
Fixed code to pass test

lat and lon input variables were placed in the wrong order.
Merge pull request #1294 from durga2112/issue-966

closes #966

this is a manual merge instead of using the github merge button because of a strange glitch on github
Merge pull request #1389 from taldcroft/numpy-sphere-dist

Use Numpy for spherical distance computations

Closes #881
Remove AngularSeparation class
Pass Angles (not radians) into sphere_dist computation for separation
Convert separation to Angle in degrees in one step, not two
Update doc example for Angle output
Update CHANGES.rst for removal of AngularSeparation
Merge pull request #1007 from taldcroft/delete-ang-sep

Remove AngularSeparation as a distinct class
Restore compatibility with Python 3.2