Added support for more rates
Added support for more rates

As some devices (I.E, RPI usb external microphone input) require different rates / chunk_sizes, it'd be nice to have it parametrized.
arvindch/speech_recognition,jjsg/speech_recognition,Python-Devs-Brasil/speech_recognition,Python-Devs-Brasil/speech_recognition,Uberi/speech_recognition,Zenohm/speech_recognition,Uberi/speech_recognition,adrianzhang/speech_recognition,arvindch/speech_recognition,jjsg/speech_recognition,adrianzhang/speech_recognition,Zenohm/speech_recognition