Icons not showing @ 2.1.0

[pctechjon]

I know there's issue 39 with probably the same issue, but I'm experiencing it in a version after 2.0.1 where it was fixed.

rails (4.2.11.1)
arctic_admin (2.1.0)
activeadmin (1.4.3)

app/assets/javascripts/active_admin.js
(active_admin/base removed already)

//= require arctic_admin/base

app/assets/stylesheets/active_admin.scss
(active_admin/base removed already)

@import "arctic_admin/base";
@import "active_admin/mixins";

config/initializers/active_admin.rb

Added:
  meta_tags_options = { viewport: 'width=device-width, initial-scale=1' }
  config.meta_tags = meta_tags_options
  config.meta_tags_for_logged_out_pages = meta_tags_options

Example screenshot of index column headers. Other icons like the arrows for the side-bar menu are also missing.

I would be open to using a CDN for the FA icons if necessary, just not sure how to configure that in ActiveAdmin.

[SimFortier11]

adding @import 'font_awesome5_webfont'; in _base.scss solves the problem
( don't forget to add font_awesome5_rails in the gemfile )

[cprodhomme]

duplicate to #39