Unify how we sort SQM Categories

spec/controllers/home_controller_spec.rb

@@ -0,0 +1,12 @@
+require 'rails_helper'
+
+describe HomeController, type: :controller do
+  let!(:categories) {
+    [create(:sqm_category, name: 'Second', sort_index: 2), create(:sqm_category, name: 'First', sort_index: 1)]
+  }
+
+  it 'fetches categories sorted by sort_index' do
+    get :index
+    expect(assigns(:categories).map(&:name)).to eql ['First', 'Second']
+  end
+end