Merge pull request #9 from chris-hudson/cleanup

Add package dependencies
Computation of Tatum
Added midi support
Add polyphonic key data from Music and Probability
Update variable names
Merge pull request #11 from chris-hudson/cleanup

Clean up
Merge pull request #12 from chris-hudson/key

Add polyphonic key data from Music and Probability
Merge branch 'master' of github.com:chris-hudson/Impromptica
Sound bug fixes
Work on keyfinding algorithm
Comply with PEP8
improved frequency finding, visual udpates
Merge with updates from master
Work on unit tests, get rid of utils imports (use subpackages directly)
Merge pull request #13 from chris-hudson/key

Work on keyfinding
Work on keyfinding tests
Comply with PEP8
Fix keyfinding, unit test
Onsets are now generated from samples and a sampling frequency
Merge pull request #14 from chris-hudson/onset_api

Onsets are now generated directly from samples and a sampling frequency