Switch from the test-construct gem (deprecated) to test_construct

spec/spec_helper.rb

@@ -3,11 +3,11 @@ $LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
 require 'homesick'
 require 'rspec'
 require 'rspec/autorun'
-require 'construct'
+require 'test_construct'
 require 'tempfile'
 
 RSpec.configure do |config|
-  config.include Construct::Helpers
+  config.include TestConstruct::Helpers
 
   config.before { ENV['HOME'] = home.to_s }