Updating BuildTools from 3.0.0-alpha1-20180730.11 to 3.0.0-alpha1-20180731.2
Updating BuildTools from 3.0.0-alpha1-20180730.11 to 3.0.0-alpha1-20180731.2

[auto-updated: buildtools]

aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore