Change JSON parser from circular-json to flatted & 1 more changes (#37)

* Change JSON parser from circular-json to flatted & 1 more changes

* Change JSON parser from circular-json
* Audited 2 vulnerabilities

* Update package.json

* Update Engine require

* There's a bunch of dependencies in this pkg requires node >=4, so I changed it to 4

* Remove and add node versions

* I have seen this pkg is not available with node 0.12 so I removed it
* I have added a popular used LTS version of node - 10

.travis.yml

@@ -1,5 +1,5 @@
  language: node_js
  node_js:
-   - 0.12
    - 4
    - 6
+   - 10