New step to choose emoji set

spec/components/step_updater_spec.rb

@@ -204,6 +204,17 @@ describe Wizard::StepUpdater do
     end
   end
 
+  context "emoji step" do
+    it "updates the fields correctly" do
+      updater = wizard.create_updater('emoji', emoji_set: "twitter")
+      updater.update
+
+      expect(updater).to be_success
+      expect(wizard.completed_steps?('emoji')).to eq(true)
+      expect(SiteSetting.emoji_set).to eq('twitter')
+    end
+  end
+
 
   context "invites step" do
     let(:invites) {