title: "No command 'ionic' found" and "workon: command not found"
body: <p>I have a weird problem in my Ubuntu 14.04.
  I was developing a mobile application using Ionic with an API using Django-Rest-Framework. After developing, I downloaded jdk and Android SDK so that I can build the mobile app into APK. I also downloaded the android dependencies or tools needed for building. After I downloaded it all, I go to my mobile app folder and type <code>ionic platform add android</code> to build it. But the terminal response with "No command 'ionic' found". Even typing <code>ionic serve</code> responses the same. I also tried to activate the virtual environment of the API using <code>workon mobile</code> but it responses with <code>workon: command not found</code>. Does anybody have an idea what might be wrong? Thanks</p>