title: gitignore doesn't ignore .suo Visual studio file
body: <p>I want to do simple thing, ignore .suo file and bin and obj folders from committing to git repo. I've created .gitignore file and it's working for bin and obj folders, but it keeps allowing .suo file committing. 
  The content of gitignore is simple:</p>
  
  <pre><code>/build/
  *.suo
  *.user
  _ReSharper.*/
  *.sdf
  bin/
  obj/
  Debug/
  Release/
  *.opensdf
  *.tlog
  *.log
  TestResult.xml
  *.VisualState.xml
  Version.cs
  Version.h
  Version.cpp
  </code></pre>
  
  <p>Firstly I've thought that the problem is that .suo file is already on the repo, so I've used set of git commands to remove it from repo:</p>
  
  <pre><code>git rm "file.suo"
  git commit -m "suo removed"
  git pull origin master
  git push origin master
  </code></pre>
  
  <p>And everything goes well, .suo is removed locally, it is removed from repo, and on the next commit it gets pushed again to repo.</p>
  
  <p>On the picture is committed .suo file.</p>
  
  <p><img src="https://i.stack.imgur.com/LhKTK.png" alt="enter image description here"></p>
  
  <p>Did anyone had a problem like this? How to solve this kind of problem? </p>