Various cleanup to run_command

* Rename fail_on_rc_non_zero to check_rc, much more succinct.
* Simplify method defintion
* Fix command module and drop shell=shell option; whether to use
  shell is determined by if args is a list.

library/facter

@@ -44,7 +44,7 @@ def main():
     )
 
     cmd = ["/usr/bin/env", "facter", "--json"]
-    rc, out, err = module.run_command(cmd, fail_on_rc_non_zero=True)
+    rc, out, err = module.run_command(cmd, check_rc=True)
     module.exit_json(**json.loads(out))
 
 # this is magic, see lib/ansible/module_common.py