title: Add external project dependency in gradle
body: <p>I am starting to migrate from ANT to <code>Gradle</code> and I have multiple projects which rely on one another. They are not all in the same path, meaning that they are not all under a single project but still they have dependencies with one another.</p>
  
  <p>I read that in <code>Gradle</code> in order to define a dependency between two projects, they need to be under the same root project.</p>
  
  <p>Can I avoid this?
  how can I give <code>project compile(..)</code> a path which is outside of the current path?</p>
  
  <p>In other words, I don't want to start changing the path of the projects, for now.</p>