title: serverless: command not found in ubuntu 16.04
body: <p>I am trying to set up the AWS Serverless framework in Ubuntu 16.04 LTS. I installed Node.js and have also installed Serverless using the following command: <code>npm install -g serverless</code> in the terminal. 
  But when I try to run <code>serverless</code> it returns an error saying <code>serverless: command not found</code>. Below is a screenshot for reference:</p>
  
  <p><img src="https://i.stack.imgur.com/nPxSm.png" alt="Command not found error"></p>