Bump node-abi to prevent dedupe (closes #135)

Author: vweevers

package.json

@@ -26,7 +26,7 @@
     "minimist": "^1.2.3",
     "mkdirp-classic": "^0.5.3",
     "napi-build-utils": "^1.0.1",
-    "node-abi": "^2.7.0",
+    "node-abi": "^2.21.0",
     "noop-logger": "^0.1.1",
     "npmlog": "^4.0.1",
     "pump": "^3.0.0",