Improve notebook testing (closes #27)
Add Make rule to strip figure memory hex identifiers
Comitting example notebooks with stripped hex ids
Update gitignore file
Fix regplot default size
Fix bug in specifying regplot scatter mew
Tweaking aesthetics notebook
Improve regplot annotation location
Reverting hex substitutions as they were causing failures
Improvements to lm tutorial; one cell is stochastically failing tests
Use fewer significant figures in corrplot
Change where lm tutorial rng is seeded for stability
Attempt to specify ipython version on travis
Add image_diff function to ipnbtest; PIL to travis install
Make image diff code more compact
More improvements to notebook testing
Further testing changes
Improve text and image diffing
Try using Bitstream Vera Sans to solve Travis issues
Try to install fonts as part of travis build