title: Sourcetree graph only show master branch
body: <p>When using sourceTree, I have created two branches under the master branch and made a commit and merge operation, but it did not appear on the Graph.<br>
  It look like this：
  <a href="https://i.stack.imgur.com/jkFz0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jkFz0.png" alt="enter image description here"></a>
  I mean why it is only show one master branch, not like this:
  <a href="https://i.stack.imgur.com/7lNH2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/7lNH2.png" alt="enter image description here"></a></p>