deps: update np to fix MFA bug during publishes (jaredpalmer#816)

- previously it would always fail the last step or few because it had a
  bug with the MFA check
  - this has been fixed in a later version, so upgrade

package.json

@@ -114,7 +114,7 @@
     "cssnano": "^4.1.10",
     "doctoc": "^1.4.0",
     "husky": "^4.2.2",
-    "np": "^6.2.0",
+    "np": "^6.4.0",
     "pretty-quick": "^2.0.0",
     "react": "^16.8.6",
     "react-dom": "^16.13.0",