Import sources from parent project

[Andrey]

Hi,
I have got this structure of my project:
> parentapp
>     dub.json
>     source
>         common.d
>     childapp1
>         dub.json
>         source
>             app.d
>             somefile.d
>     childapp2
>         dub.json
>         source
>             app.d

The "childapp1" and "childapp2" are standanole subprograms. I 
want to import file "common.d" in both "app.d". How to do it 
correctly?

I tried to write "import common;" but got error: " Error: module 
`common` is in file 'common.d' which cannot be read".
In "parentapp/dub.json" I also added these lines:
> "dependencies": {
>     "parentapp:childapp1": "*",
>     "parentapp:childapp2": "*"
> },
> "subPackages": [
>     "./childapp1/",
>     "./childapp2/"
> ]