Codiad unmaintained (#1552)

Per the developer, this is no longer maintained: 
https://github.com/Codiad/Codiad/issues/1071#issuecomment-418750764

README.md

@@ -1175,7 +1175,6 @@ See **[Ticketing](#ticketing)**
 ### IDE/Tools
 
 - [Babelfish](https://doc.bblf.sh) - Self-hosted server for source code parsing. It can parse any file, in any supported language, extract an Abstract Syntax Tree from it, and convert it to a Universal Abstract Syntax Tree which can enable further analysis and transformation. ([Source Code](https://github.com/bblfsh/)) `GPL-3.0` `Go`
-- [Codiad](http://codiad.com/) - Web-based IDE framework with a small footprint and minimal requirements. ([Source Code](https://github.com/Codiad/Codiad)) `MIT` `PHP`
 - [Eclipse Che](http://www.eclipse.org/che/) - Open source workspace server and cloud IDE. ([Source Code](https://github.com/eclipse/che)) `EPL-1.0` `Docker/Java`
 - [ICEcoder](https://icecoder.net/) - ICEcoder is a web IDE / browser based code editor, which allows you to develop websites directly within the web browser. ([Demo](http://demo.icecoder.net/ICEcoder/), [Source Code](https://github.com/mattpass/ICEcoder)) `MIT` `PHP`
 - [JS Bin](http://jsbin.com/) - Open source collaborative web development debugging tool. ([Source Code](https://github.com/jsbin/jsbin)) `MIT` `Nodejs`