Use GCC 6 for Node 12 binaries
Use GCC 6 for Node 12 binaries

Node 12 is built using GCC 6 therefore
it is mandatory that we use the same C++
runtime as the mothership.

nschonni/node-sass,nschonni/node-sass,xzyfer/node-sass,nschonni/node-sass,xzyfer/node-sass,nschonni/node-sass,xzyfer/node-sass,sass/node-sass,sass/node-sass,saper/node-sass,saper/node-sass,xzyfer/node-sass,xzyfer/node-sass,sass/node-sass,saper/node-sass,sass/node-sass,xzyfer/node-sass,saper/node-sass,sass/node-sass,saper/node-sass,sass/node-sass,saper/node-sass,xzyfer/node-sass,nschonni/node-sass,sass/node-sass,nschonni/node-sass,saper/node-sass,nschonni/node-sass