Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
	Dockerfile
	app/javascript/packs/common.js
	config/webpack/loaders/sass.js
	config/webpack/shared.js
	db/schema.rb
	package.json
	yarn.lock

A lot of the conflicts come from updating webpack.

Even though upstream deleted app/javascript/packs/common.js, I kept
glitch-soc's version as it unifies JS/CSS packs behavior across flavours.

Ported glitch changes to webpack 4.x

db/migrate/20180514140000_revert_index_change_on_statuses_for_api_v1_accounts_account_id_statuses.rb

@@ -5,7 +5,7 @@ class RevertIndexChangeOnStatusesForApiV1AccountsAccountIdStatuses < ActiveRecor
 
   def change
     safety_assured do
-      add_index :statuses, [:account_id, :id, :visibility, :updated_at], order: { id: :desc }, algorithm: :concurrently, name: :index_statuses_20180106 unless index_exists?(:statuses, name: "index_statuses_20180106")
+      add_index :statuses, [:account_id, :id, :visibility, :updated_at], order: { id: :desc }, algorithm: :concurrently, name: :index_statuses_20180106 unless index_name_exists?(:statuses, "index_statuses_20180106")
     end
 
     # These index may not exists (see migration 20180514130000)

db/migrate/20180711152640_create_relays.rb

@@ -0,0 +1,12 @@
+class CreateRelays < ActiveRecord::Migration[5.2]
+  def change
+    create_table :relays do |t|
+      t.string :inbox_url, default: '', null: false
+      t.boolean :enabled, default: false, null: false, index: true
+
+      t.string :follow_activity_id
+
+      t.timestamps
+    end
+  end
+end