enable prebuild for Node 12

Author: shiftkey

package.json

@@ -34,7 +34,7 @@
     "lint": "npm run cpplint",
     "cpplint": "node-cpplint --filters legal-copyright,build-include,build-namespaces src/*.cc",
     "test": "npm run lint && npm build . && mocha --require babel-core/register spec/",
-    "prebuild-node": "prebuild -t 6.11.0 -t 7.9.0 -t 8.9.0 -t 9.4.0 -t 10.11.0 -t 11.9.0 --strip",
+    "prebuild-node": "prebuild -t 6.11.0 -t 7.9.0 -t 8.9.0 -t 9.4.0 -t 10.11.0 -t 11.9.0 -t 12.0.0 --strip",
     "prebuild-node-ia32": "prebuild -t 6.11.0 -t 7.9.0 -t 8.9.0 -t 9.4.0 -a ia32 --strip",
     "prebuild-electron": "prebuild -t 1.6.11 -t 1.7.10 -t 1.8.0 -t 2.0.0 -t 3.0.0 -t 4.0.4 -r electron --strip",
     "prebuild-electron-ia32": "prebuild -t 1.6.11 -t 1.7.10 -t 1.8.0 -t 2.0.0 -t 3.0.0 -t 4.0.4 -r electron -a ia32 --strip",