Increase spec timeout
Increase spec timeout

LibSass builds on AppVeyor are failing due to `spec/scss/huge`
timing out.

am11/sass-spec,mgreter/sass-spec,sass/sass-spec,xzyfer/sass-spec,nschonni/sass-spec,sass/sass-spec,nschonni/sass-spec,am11/sass-spec,mgreter/sass-spec,xzyfer/sass-spec,mgreter/sass-spec,sass/sass-spec,am11/sass-spec,xzyfer/sass-spec,sass/sass-spec,nschonni/sass-spec,xzyfer/sass-spec,nschonni/sass-spec