Optimized n+1 queries in accounts Atom and HTML views

Added stack trace for SQL queries in development
Removed badly thought out accounts/lookup API

spec/controllers/api/accounts/lookup_controller_spec.rb

@@ -1,24 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe Api::Accounts::LookupController, type: :controller do
-  render_views
-
-  let(:user)  { Fabricate(:user, account: Fabricate(:account, username: 'alice')) }
-  let(:token) { double acceptable?: true, resource_owner_id: user.id }
-
-  before do
-    allow(controller).to receive(:doorkeeper_token) { token }
-  end
-
-  describe 'GET #index' do
-    before do
-      Fabricate(:account, username: 'bob')
-      Fabricate(:account, username: 'mcbeth')
-      get :index, params: { usernames: 'alice,bob,mcbeth' }
-    end
-
-    it 'returns http success' do
-      expect(response).to have_http_status(:success)
-    end
-  end
-end