Improve ChefSpec test speed by enabling caching

This updates all references of let(:chef_run) to cached(:chef_run) to
speed up tests. By doing this, we have to create a new cached(:chef_run)
block whenever we need to adjust node attributes for testing.

Speed was improved from 1 minute 14.88 to 21.64 seconds

Change-Id: Iff9c0f56d17e8f2924b4126144ed116081278842

spec/setup-redhat_spec.rb

@@ -5,18 +5,25 @@ describe 'openstack-integration-test::setup' do
   describe 'redhat' do
     let(:runner) { ChefSpec::SoloRunner.new(REDHAT_OPTS) }
     let(:node) { runner.node }
-    let(:chef_run) do
+    cached(:chef_run) do
       runner.converge(described_recipe)
     end
 
     include_context 'tempest-stubs'
 
     it 'installs tempest dependencies' do
-      %w(git curl libxslt-devel
-         libxml2-devel python-testrepository
-         libffi-devel python-devel
-         python-gabbi python-testscenarios
-         python-ddt).each do |pkg|
+      %w(
+        curl
+        git
+        libffi-devel
+        libxml2-devel
+        libxslt-devel
+        python-ddt
+        python-devel
+        python-gabbi
+        python-testrepository
+        python-testscenarios
+      ).each do |pkg|
         expect(chef_run).to upgrade_package(pkg)
       end
     end

spec/setup_spec.rb

@@ -5,7 +5,7 @@ describe 'openstack-integration-test::setup' do
   describe 'ubuntu' do
     let(:runner) { ChefSpec::SoloRunner.new(UBUNTU_OPTS) }
     let(:node) { runner.node }
-    let(:chef_run) do
+    cached(:chef_run) do
       runner.converge(described_recipe)
     end
 
@@ -187,9 +187,8 @@ describe 'openstack-integration-test::setup' do
       end
     end
 
-    describe 'tempest.conf with HTTPS' do
-      let(:runner) { ChefSpec::SoloRunner.new(UBUNTU_OPTS) }
-      let(:chef_run) do
+    context 'tempest.conf with HTTPS' do
+      cached(:chef_run) do
         runner.node.override['openstack']['endpoints']['internal']['identity']['scheme'] = 'https'
         runner.converge(described_recipe)
       end

spec/spec_helper.rb

@@ -1,24 +1,21 @@
 # encoding: UTF-8
 require 'chefspec'
 require 'chefspec/berkshelf'
-
-ChefSpec::Coverage.start! { add_filter 'openstack-integration-test' }
-
 require 'chef/application'
 
 RSpec.configure do |config|
   config.color = true
   config.formatter = :documentation
-  config.log_level = :fatal
+  config.log_level = :warn
 end
 
 REDHAT_OPTS = {
   platform: 'redhat',
-  version: '7.4',
+  version: '7',
 }.freeze
 UBUNTU_OPTS = {
   platform: 'ubuntu',
-  version: '16.04',
+  version: '18.04',
 }.freeze
 
 shared_context 'tempest-stubs' do