Removed nitrous.io

Discontinued on 14th November 2016

README.md

@@ -516,7 +516,6 @@ Table of Contents
    * [koding.com](http://www.koding.com/) — Cloud-based development environment. You have a Ubuntu OS machine
    * [codeanywhere.com](https://codeanywhere.com/) — Full IDE in the browser and mobile apps. Access FTP, SFTP, Dropbox, Google Drive, GitHub and BitBucket. Hosted virtual machines with terminal access. Collaboration features like share links, live editing, permissions and version tracking
    * [codenvy.com](https://codenvy.com/) — IDE and automated developer workspaces in a browser, collaborative, Git/SVN integration, build and run your app in customizable Docker-based runners (free tier includes: 4 GB RAM, always-on machines, ability to run multiple machines simultaneously), pre-integrated deploy to Google Apps
-   * [nitrous.io](https://nitrous.io/) — Private Linux instance(s) with interactive collaboration, free for 2 hours/day. {[More Details](http://goo.gl/J1Zbsg)}
    * [visualstudio.com](http://visualstudio.com/community) — Fully-featured IDE with thousands of extensions, cross-platform app development (Microsoft extensions available for download for iOS and Android), desktop, web and cloud development, multi-language support (C#, C++, JavaScript, Python, PHP and more)
    * [code.visualstudio.com](http://code.visualstudio.com/) — Build and debug modern web and cloud applications. Code is free, Open Source and available on your favorite platform, Linux, Mac OSX and Windows
    * [cloud.sagemath.com](https://cloud.sagemath.com/) — Collaborative mathematics-oriented IDE in a browser, with support for Python, LaTeX, IPython Notebooks, etc