chore: license checking in posttest

This can't be checked in until a license issue with
`@google-cloud/common-grpc` is fixed. It has a transitive dependency,
`jsonify`, which has "Public Domain" as its license. But Public Domain
is not a valid license for Google's open source projects.

Also the 'log-driver' package is whitelisted.

Additonal minor changes:
- add the `version` field: this is a required field
- fix the `private` field: this is a boolean field. "true" --> true.
- package-lock.json is committed.

Author: jinwoo

js-green-licenses.json

@@ -0,0 +1,5 @@
+{
+  "packageWhitelist": [
+    "log-driver"
+  ]
+}