title: Creating a pull request in Bitucket: error "Unrelated branches"
body: <p>I'm having a small team working on a single repository, I asked my each teammates to create there own branch and work on there branch, all of them cloned the repository and then they did the following command:</p>
  
  <pre><code>git checkout -b BitPankaj
  </code></pre>
  
  <p><code>BitPankaj</code> is illustration branch name, they started working on this branch and uploaded there work through </p>
  
  <pre><code>git branch --set-upstream origin BitPankaj
  </code></pre>
  
  <p>Now in my repository I can see that those branch appears and their commits are also visible:</p>
  
  <p><a href="https://i.stack.imgur.com/cmh5S.png" rel="noreferrer"><img src="https://i.stack.imgur.com/cmh5S.png" alt="commits section"></a></p>
  
  <p>and Branches:</p>
  
  <p><a href="https://i.stack.imgur.com/an1KG.png" rel="noreferrer"><img src="https://i.stack.imgur.com/an1KG.png" alt="branches section"></a></p>
  
  <p>Now each one of them where trying to create a pull request to review there code and merge to master branch. so they tried doing something like this:</p>
  
  <p>But it throws an error of unrelated branches:</p>
  
  <blockquote>
    <p>The following error(s) occurred saving this pull request: Unrelated branches</p>
  </blockquote>
  
  <p><a href="https://i.stack.imgur.com/bVJDD.png" rel="noreferrer"><img src="https://i.stack.imgur.com/bVJDD.png" alt="pull request error"></a></p>
  
  <p>We people are learning to work on git, help me out with this.</p>