Hi Marwan,
If I remember correctly, you can keep myapp outside of GOPATH and it should work.
Another option is to create your app directory, the one with handlers, as a leaf package with no sub-directories:
myuser/
myproject/
pkg1/
pkg2/
app/
handlers.go
app.yaml
In app/handlers.go you can safely import
github.com/myuser/myproject/pkg1 for instance. As long as app does not have any "child" packages this should work and you can keep your business logic reusable while deploying your app safely from
GOPATH. This is what I use currently.
From handlers.go you import your handler. Since all will be in GOPATH and with proper imports, your autocomplete should work as expected.