first attempt at making docs
basic documentation for slicing and changing units
fixed image repeating issue, only has docs for slicing now
small changes
fixed some links,added doc for changing units
wrapped lines at 79 characters
described header information in more detail
Merge pull request #52 from anizami/add-docs

Added documentation for slicing data cubes
Make sure infrastructure files get excluded from coverage testing, and ported over fix to edit-on-github feature from astropy affiliated package template.
Remove unused code
Exclude six.py from coverage tests
Merge pull request #59 from astrofrog/infrastructure-fixes

Make sure infrastructure files get excluded from coverage testing
Updated README.md
axis labels are now placed similar to matplotlib
cleaned up comments, unused code etc
forgot to update ticks_labels reference image
testing minpad on overlay_features.png
added documentation for minpad