Set fixture paths for unit tests

This change defines manifest_dir and module_path expicitly in unit
tests so that modules installed under fixtures directory is properly
loaded.

Closes-Bug: #1930403
Change-Id: I64316e1bb130c9bba96cfa77ee2a2971363dcd97
(cherry picked from commit 0d07da0981)

spec/spec_helper.rb

@@ -2,9 +2,14 @@ require 'puppetlabs_spec_helper/module_spec_helper'
 require 'shared_examples'
 require 'puppet-openstack_spec_helper/facts'
 
+fixture_path = File.expand_path(File.join(File.dirname(__FILE__), 'fixtures'))
+
 RSpec.configure do |c|
   c.alias_it_should_behave_like_to :it_configures, 'configures'
   c.alias_it_should_behave_like_to :it_raises, 'raises'
+
+  c.module_path = File.join(fixture_path, 'modules')
+  c.manifest_dir = File.join(fixture_path, 'manifests')
 end
 
 at_exit { RSpec::Puppet::Coverage.report! }