Merge pull request #36 from siculars/master

median absolute deviation (mad)
Initial addition of z_score and cumulative_std_normal_probability
Document MAD, fixes #35
Version 0.4.0
Tweak comments, style
Merge branch 'doronlinder-normal_distribution'
Add z_score and normal distribution documentation sketch.
Expose normal table, bump version, fill CHANGELOG
added t-test for two samples: test differences in mean value
more robust checks conditions and check script
code style polished
Idiomatic javascript and fixes
Rebuild documentation
Add bower.json
Bump version number
Merge pull request #45 from KyleAMathews/patch-1

Add bower.json
Merge pull request #46 from KyleAMathews/patch-2

Bump version number
Add instructions for bower to README.md
Merge pull request #47 from KyleAMathews/patch-3

Add instructions for bower to README.md
Update mocha and chai