Add potential work-around for expect on macOS.

http://pexpect.readthedocs.io/en/stable/commonissues.html#truncated-output-just-before-child-exits

(cherry picked from commit 0c7602fb59)

test/integration/targets/expect/tasks/main.yml

@@ -57,7 +57,7 @@
 
 - name: test chdir
   expect:
-    command: "pwd"
+    command: "/bin/sh -c 'pwd && sleep 1'"
     chdir: "{{output_dir}}"
     responses:
       foo: bar