Bump nan from 2.12.1 to 2.13.2 (#179)

Bumps [nan](https://github.com/nodejs/nan) from 2.12.1 to 2.13.2.
- [Release notes](https://github.com/nodejs/nan/releases)
- [Changelog](https://github.com/nodejs/nan/blob/master/CHANGELOG.md)
- [Commits](nodejs/nan@v2.12.1...v2.13.2)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -52,7 +52,7 @@
     "prebuild": "^8.2.1"
   },
   "dependencies": {
-    "nan": "2.12.1",
+    "nan": "2.13.2",
     "prebuild-install": "5.3.0"
   }
 }