updated readme to new org name
updated readme to new org name

MicrosoftGenomics/FaST-LMM,zhonghualiu/FaST-LMM,zhonghualiu/FaST-LMM,MicrosoftGenomics/FaST-LMM,zhonghualiu/FaST-LMM,MicrosoftGenomics/FaST-LMM