Add a test for emojis_controller (#7652)

spec/controllers/emojis_controller_spec.rb

+require 'rails_helper'
+
+describe EmojisController do
+  render_views
+
+  let(:emoji) { Fabricate(:custom_emoji) }
+
+  describe 'GET #show' do
+    subject(:responce) { get :show, params: { id: emoji.id, format: :json } }
+    subject(:body) { JSON.parse(response.body, symbolize_names: true) }
+
+    it 'returns the right response' do
+      expect(responce).to have_http_status 200
+      expect(body[:name]).to eq ':coolcat:'
+    end
+  end
+end