Run `puppet generate types` if there are custom types

[ekohl]

puppetlabs/puppetlabs-concat#759 shows a case where a refactor broke puppet generate types. Running this in an acceptance test would help and mirror real deployments closer. It should be done after all modules have been installed, so after this bit:

voxpupuli-acceptance/lib/voxpupuli/acceptance/spec_helper_acceptance.rb

Lines 32 to 39 in 993d0d0

	case modules
	when :metadata
	install_module
	install_module_dependencies
	when :fixtures
	fixture_modules = File.join(Dir.pwd, 'spec', 'fixtures', 'modules')
	Voxpupuli::Acceptance::Fixtures.install_fixture_modules_on(hosts, fixture_modules)
	end