title: How to keep different values (commits) on separate branches?
body: <p>I believe situation I'm describing is pretty common and basic, yet I can't find soultion for it.</p>
  
  <p>I'm developing a web app and I have git repository for it. There is a production version of the app, the code of which I keep on master branch and there are branches for open developments.</p>
  
  <p>What I want to achieve is:</p>
  
  <ul>
  <li>I want to have some values (like connection strings) different on master branch and development branches.</li>
  <li>I want to be able to merge those branches (when the development is reade to be published) in a way I don't worry about values mentioned aboved. So the connection string from development branch doesn't override the connection string from production version</li>
  <li>The ideal solution would also take care of replacing the connection (from PROD database to DEV) string while creating new branch.</li>
  </ul>
  
  <p>I figured out a way to do it would be a commit with those changes on development branches, that would be marked not to be included in merge, but I couldn't find a way to do it.</p>
  
  <p>I'd appreciate any advice.</p>