[0.7] Fix build errors, node14 compatability

[3nprob]

• Fix build errors on Linux (even on a vanilla nodev12 it wouldn't build without the extra cflags)
• Upgrade insecure and deprecated dependencies (replace queue-async with d3-queue)
• Upgrade other dependencies for nodev14 compatability
• Change from c++14 to gnu++14 to resolve build errors on certain platforms
• Add binary upload for nodejs v14 to travis CI

It would be great if this could make it into a release