Plugins UI needs 'dynamic_form'

closes CNVS-19816

make sure we have a spec to check rendering of the plugins
setting view from now on, and explicitly require 'dynamic_form'
in the plugins controller

also removes a linter that shouldn't be on for
describing classes (or views in this case)

TEST PLAN:
 1) go configure any plugin
 2) it should not explode

Change-Id: I32e58a524ddb18b922ba79e20e9e7b9c1f2a8f07
Reviewed-on: https://gerrit.instructure.com/52216
Reviewed-by: Cody Cutrer <cody@instructure.com>
Tested-by: Jenkins
QA-Review: Ethan Vizitei <evizitei@instructure.com>
Product-Review: Ethan Vizitei <evizitei@instructure.com>

.rubocop.yml

@@ -109,5 +109,7 @@ RSpec/ExampleWording:
   Enabled: false
 RSpec/DescribedClass:
   Enabled: false
+RSpec/DescribeClass:
+  Enabled: false
 Style/HashSyntax:
   Enabled: false

app/controllers/plugins_controller.rb

@@ -15,6 +15,7 @@
 # You should have received a copy of the GNU Affero General Public License along
 # with this program. If not, see <http://www.gnu.org/licenses/>.
 #
+require 'dynamic_form'
 
 class PluginsController < ApplicationController
   before_filter :require_setting_site_admin, :set_site_admin_context, :set_navigation

spec/views/plugins/show.html.erb_spec.rb

@@ -0,0 +1,20 @@
+require File.expand_path(File.dirname(__FILE__) + '/../../spec_helper')
+require File.expand_path(File.dirname(__FILE__) + '/../views_helper')
+
+describe "plugins/show" do
+  it "renders without exploding" do
+    plugin = stub(
+      id: 'some_plugin',
+      name: "Some Plugin",
+      settings_partial: "settings_header"
+    )
+    plugin_setting = PluginSetting.new()
+
+    assigns[:plugin] = plugin
+    assigns[:plugin_setting] = plugin_setting
+    view.stubs(:plugin_path).returns("/some/path")
+    view.stubs(:params).returns({id: 'some_plugin'})
+    render 'plugins/show'
+    expect(response.body).to match("Return to plugins list")
+  end
+end