I'm trying to add a subproject to my Play Framework project, and find the docs generally lacking there. 

I've created a play project, let's call it `my-web`, and it's in directory `/my-cool-project/web`. I also have another project I would like `my-web` to depend on, let's call it `my-model`. `my-model` a git submodule for `my-cool-project`, and when I pull it, my directory structure is

```
/my-cool-project
     /my-web
         /app
         /conf
         build.sbt
     /my-model
         /main
              /java
                   /src

```

Now, how do I add `my-model` as a subproject for `my-web`? I've tried 

```
lazy val myModel = project.in(file("../my-model"))

```

but all I get is that `my-model` is not contained within the build root of `my-web`... Anything else I can try in build.sbt?