update README
refactor bytearray copying, make it easier to be optimized by compiler
bump encoder-mp3
bump encoder-mp3 to gain better size optimization
make download always return bytearray, converting bytearray to something for external use should be done in interoperator
implemented #19, partially implemented #6
#6 remove annoying logging
add features section
implemented #6, support upsampling now
Release 0.2.7