Pypianoroll v1.0.4

• Add method Track.binarize
• Remove method StandardTrack.binarize
• Fix a bug in Multitrack.trim (tempo and downbeat arrays now also get trimmed)
• Track.standardize now clips the piano roll to [0, 127] before casting to uint8
• Calculate tempo using harmonic mean in MIDI output (#15)
• Show data types of arrays in Multitrack.__repr__ and Track.__repr__
• Cast name, program and is_drum to proper types in MIDI input