Import wdl from GCS

Hello-
I'm trying to a get a pipeline up and running in FC and can't seem to figure out wdl imports. I'd like to have the main method as a simple wdl that imports various other sub-workflows that are commonly used by different pipelines (like QC or format conversions). Rather than copy-pasting the common tasks in every pipeline, they're stored in a google bucket and should simply be imported by some hardcoded url.

When I try to test this locally with test.wdl:

import "http://path/to/wdl.wdl" as subwf

workflow wf {
  call subwf.task1
}

calling :

java -jar wdltool-0.12.jar validate test.wdl

It seems that the url is being interpreted as a local path:

Failed to import workflow http://path/to/wdl.wdl.:
File not found /Users/tmajaria/http://path/to/wdl.wdl

This same problem occurs using the GCS link (gs://path/to/something). So basically, are urls supported in import statements? Or is there another method for importing wdls from some remote repo when running in FC?

Thanks!