update sinatra, references
update sinatra, references
brogersyh/Dockerfiles-for-windows,brogersyh/Dockerfiles-for-windows,mdragan/Virtualization-Documentation,brogersyh/Dockerfiles-for-windows,mebersol/Virtualization-Documentation,brogersyh/Dockerfiles-for-windows,brogersyh/Dockerfiles-for-windows