[puppet][legacy] fix spec tests for older puppets.

Author: truthbk

spec/defines/datadog_agent__integration_spec.rb

@@ -15,6 +15,11 @@
     }}
     it { should compile }
     it { should contain_file('/etc/dd-agent/conf.d/test.yaml').with_content(/init_config: /) }
-    it { should contain_file('/etc/dd-agent/conf.d/test.yaml').with_content(/---\ninit_config: \ninstances:\n- one: two\n/) }
+    gem_spec = Gem.loaded_specs['puppet']
+    if gem_spec.version >= Gem::Version.new('4.0.0')
+      it { should contain_file('/etc/dd-agent/conf.d/test.yaml').with_content(/---\ninit_config: \ninstances:\n- one: two\n/) }
+    else
+      it { should contain_file('/etc/dd-agent/conf.d/test.yaml').with_content(/--- \n  init_config: \n  instances: \n    - one: two/) }
+    end
     it { should contain_file('/etc/dd-agent/conf.d/test.yaml').that_notifies("Service[datadog-agent]") }
 end