Error handling for notebooks with invalid format
Undo change made to example nb for testing
Changed error message
Flake8 style fixes
Added/fixed error handling
Add note on current stability :-)
Changed when error handling messages appear and fixed code so that we don't try and send the notebook to the flask after the format is invalid
Fix notebook should not be sent to flask if invalid type
Add --check argument for profiling/testing purposes.
Run nbdiff and nbmerge commands on travis.
Fix test-merge script.
Configure git in travis build so the scripts work.
Remove python 2.6 from build.
Merge pull request #172 from tarmstrong/test-commands-travis

Run nbdiff/nbmerge commands in travis build
Flake8 style fix
Merge branch 'master' into error_handling
List the filename when there is an invalid notebook
Flake8 style fixes
Merge branch 'error_handling' of github.com:selenaaa/nbdiff into error_handling
Add merge example with invalid notebook file for testing #169