cleanup readme file and updates travis config file

.travis.yml

@@ -1,19 +1,14 @@
 language: node_js
 node_js:
   - "node"
-  - "4"
+  - "7"
   - "6"
+  - "4"
 sudo: false
 git:
   depth: 10
 branches:
   only:
     - master
-notifications:
-  webhooks:
-    urls:
-      - https://webhooks.gitter.im/e/7edad70ac7ee4dc6d017
-    on_success: always
-    on_failure: always
 script: "npm run-script test-ci"
 after_script: "cat ./coverage/lcov.info | coveralls"

README.md

@@ -1,13 +1,9 @@
 # json-cycle
 
-[![Join the chat at https://gitter.im/valery-barysok/json-cycle][gitter-join-chat-image]][gitter-channel-url]
 [![NPM Version][npm-version-image]][npm-url]
 [![NPM Downloads][npm-downloads-image]][npm-url]
 [![Node.js Version][node-image]][node-url]
-
 [![Build Status][travis-image]][travis-url]
-[![Dependency Status][dependencies-image]][dependencies-url]
-[![devDependency Status][dev-dependencies-image]][dev-dependencies-url]
 [![Coverage Status][coveralls-image]][coveralls-url]
 
 Utilities provide ability to encode/decode circular structures for converting to and from JSON.
@@ -116,14 +112,8 @@ MIT © 2015-... Valery Barysok, Douglas Crockford
 [npm-url]: https://npmjs.org/package/json-cycle
 [travis-image]: https://img.shields.io/travis/valery-barysok/json-cycle/master.svg?style=flat-square
 [travis-url]: https://travis-ci.org/valery-barysok/json-cycle
-[dependencies-image]: https://david-dm.org/valery-barysok/json-cycle.svg?style=flat-square
-[dependencies-url]: https://david-dm.org/valery-barysok/json-cycle
-[dev-dependencies-image]: https://david-dm.org/valery-barysok/json-cycle/dev-status.svg?style=flat-square
-[dev-dependencies-url]: https://david-dm.org/valery-barysok/json-cycle#info=devDependencies
 [coveralls-image]: https://img.shields.io/coveralls/valery-barysok/json-cycle/master.svg?style=flat-square
 [coveralls-url]: https://coveralls.io/r/valery-barysok/json-cycle?branch=master
 [node-image]: https://img.shields.io/node/v/json-cycle.svg?style=flat-square
 [node-url]: http://nodejs.org/download/
-[gitter-join-chat-image]: https://badges.gitter.im/Join%20Chat.svg?style=flat-square
-[gitter-channel-url]: https://gitter.im/valery-barysok/json-cycle
 [jsonjs-url]: https://github.com/douglascrockford/JSON-js