[#394] Added users.tags and admin routes to tag and untag users. Added tests.

priv/repo/migrations/20181206125616_add_tags_to_users.exs

@@ -0,0 +1,11 @@
+defmodule Pleroma.Repo.Migrations.AddTagsToUsers do
+  use Ecto.Migration
+
+  def change do
+    alter table(:users) do
+      add :tags, {:array, :string}
+    end
+
+    create index(:users, [:tags], using: :gin)
+  end
+end