This fixes the PostgreSQL setup when using Windows as Docker host. Because git by default will transform all files to Windows line-endings on clone, the files mounted inside the Linux based PostgreSQL container can't be read correctly and the initialisation fails.
Closes#10.
This should solve permission issues that can occur in some cases (e.g.
on Windows PostgreSQL can complain about an ownership mismatch of the
/var/lib/postgresql/data directory).
