title: Cannot push to git repository
body: <p>I keep getting this error message from git while pushing, even I am trying it after pulling over and over again:</p>
  
  <pre> ! [rejected]        master -> master (non-fast-forward)
  error: failed to push some refs to '[repo url]'
  To prevent you from losing history, non-fast-forward updates were rejected
  Merge the remote changes (e.g. 'git pull') before pushing again.  See the
  'Note about fast-forwards' section of 'git push --help' for details.</pre>
  
  <p>Here is what the branch history looks like:</p>
  
  <pre><code>A---B---C
    |   |
    D   E-F
  
  A initial commit (me)
  B some commit (me)
  C master
  D some commit (other dev)
  E remotes/origin/master - Merge branch 'master' of [repo url]
  F Local uncommitted changes, not checked into an index
  </code></pre>
  
  <p>From here, when I pull, nothing comes. When I push, I get the error. How can I successfully push again?</p>