Introduce User#experience_cs_admin? method

I'm planning to make use of this to grant access to
`Api::PublicProjectsController#create` so that admin users on the
`experience-cs` website can create public Scratch projects via the
`editor-api` API.

Author: floehopper

app/models/user.rb

@@ -54,6 +54,10 @@ def admin?
     parsed_roles.include?('editor-admin')
   end
 
+  def experience_cs_admin?
+    parsed_roles.include?('experience-cs-admin')
+  end
+
   def parsed_roles
     roles&.to_s&.split(',')&.map(&:strip) || []
   end

spec/models/user_spec.rb

@@ -311,6 +311,18 @@
     end
   end
 
+  describe '#experience_cs_admin?' do
+    it 'returns true if the user has the experience-cs-admin role in Hydra' do
+      user = build(:user, roles: 'experience-cs-admin')
+      expect(user).to be_experience_cs_admin
+    end
+
+    it 'returns false if the user does not have the experience-cs-admin role in Hydra' do
+      user = build(:user, roles: 'another-admin')
+      expect(user).not_to be_experience_cs_admin
+    end
+  end
+
   describe '#school_roles' do
     subject(:user) { build(:user) }