GNUVID v2.4 update

update %Ns and seq length cutoffs

Add NCBI test sequences

VOC

GNUVID Machine Learning Random Forest Classifier v2.0.

GNUVID DB update v1.4

GNUVID v1.3

Globally circulating clonal complexes as of 2020-06-17 (18298 genomes)

Updating README.md

Update README.md