Merge pull request #3013 from mattclay/apt-check-mode

Do not install python-apt in check mode.

packaging/os/apt.py

@@ -579,6 +579,8 @@ def main():
     module.run_command_environ_update = APT_ENV_VARS
 
     if not HAS_PYTHON_APT:
+        if module.check_mode:
+            module.fail_json(msg="python-apt must be installed to use check mode")
         try:
             module.run_command('apt-get update && apt-get install python-apt -y -q --force-yes', use_unsafe_shell=True, check_rc=True)
             global apt, apt_pkg