title: Git: Push rejected
body: <p>I have a team and we are working on a project. One of our teammembers created a repository on GitHub and add others as collaborators. My team member committed our code to this repository. I did changes in my part and when I try to commit it, I have an error. How can I commit changes to a repository in which I'm a collaborator?</p>
  
  <p>That is what I did:</p>
  
  <pre><code>git remote add origin https://github.com/xxx/xxx.git (added a repository where I'm a collaborator)
  
  `git push origin master
  To https://github.com/xxx/xxx.git
  ! [rejected]        master -&gt; master (fetch first)  
  error: failed to push some refs to 'https://github.com/xxx/xxx.git'
  hint: Updates were rejected because the remote contains work that you do
  hint: not have locally. This is usually caused by another repository pushing
  hint: to the same ref. You may want to first integrate the remote changes
  hint: (e.g., 'git pull ...') before pushing again.
  hint: See the 'Note about fast-forwards' in 'git push --help' for details. 
  
  git pull origin master
  warning: no common commits
  remote: Counting objects: 145, done.
  remote: Compressing objects: 100% (60/60), done.
  remote: Total 145 (delta 67), reused 145 (delta 67), pack-reused 0
  Receiving objects: 100% (145/145), 55.90 KiB | 0 bytes/s, done.
  Resolving deltas: 100% (67/67), done.
  From https://github.com/xxx/xxx
  * branch            master     -&gt; FETCH_HEAD
  * [new branch]      master     -&gt; or/master
  fatal: refusing to merge unrelated histories
  </code></pre>
  
  <p>I just want to update my part and commit it to the repository. I dont have my own repository.</p>
  
  <p>Thank you</p>