update package.json for new version of nan

[risacher]

fixes #194 and #195

[wwwy3y3]

+1 on this PR. kudos to @risacher.

For people bumped into related issues and still waiting for this PR, you can use npm-shrinkwrap to force the nan version.

Example:

{
  "name": "<your package name>",
  "version": "<your package version>",
  "lockfileVersion": 1,
  "dependencies": {
    "pty.js": {
      "version": "0.3.1",
      "from": "pty.js@0.3.1",
      "dependencies": {
        "nan": {
          "version": "2.12.1",
          "from": "nan@2.12.1"
        }
      }
    }
  }
}