Gtk.jl fails when used in Juno (Atom) on Ubuntu 16.04

[Sleort]

Sorry if this is not the right place to ask, but...

using Gtk.jl works fine in the REPL, but fails (never finishes to first time compile) with the following error message in Juno on Ubuntu 16.04:

(julia:27582): Gtk-WARNING **: GTK+ module /snap/atom/50/usr/lib/x86_64-linux-gnu/gtk-2.0/modules/libunity-gtk-module.so cannot be loaded.
GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported.
Gtk-Message: Failed to load module "unity-gtk-module"

It worked fine a few days ago (through using Plots; plotlyjs()), so I'm not quite sure what's going on now... Any ideas?