Touch Account when adding or removing a Tag

so we can properly cache the tags partial using account as part of the key.

app/models/tag.rb

@@ -1,7 +1,7 @@
 class Tag < ApplicationRecord
   include Filterable
 
-  belongs_to :account, default: -> { Current.account }
+  belongs_to :account, default: -> { Current.account }, touch: true
 
   has_many :taggings, dependent: :destroy
   has_many :bubbles, through: :taggings

test/models/tag_test.rb

@@ -1,7 +1,15 @@
 require "test_helper"
 
 class TagTest < ActiveSupport::TestCase
-  # test "the truth" do
-  #   assert true
-  # end
+  test "creating or deleting a tag touches the account, so tags dialog fragment cache is invalidated" do
+    account = accounts("37s")
+
+    assert_changes -> { account.reload.updated_at } do
+      account.tags.create!(title: "ReleaseBlocker")
+    end
+
+    assert_changes -> { account.reload.updated_at } do
+      account.tags.find_by(title: "ReleaseBlocker").destroy
+    end
+  end
 end