Updated Typos in devstack

(1/5) Updated HACKING.rst for typos
(2/5) Updated typos in lib/dlm
(3/5) Updated typos in lib/ironic
(4/5) Updated typos in unittest.sh
(5/5) Updated typos in test_meta_config.sh

Change-Id: I7aafa3af69df9dc6a5923a8557f380d48b73433a
diff --git a/lib/dlm b/lib/dlm
index f68ee26..95e9b0a 100644
--- a/lib/dlm
+++ b/lib/dlm
@@ -46,7 +46,7 @@
 # - cleanup_dlm
 
 # This should be declared in the settings file of any plugin or
-# service that needs to have a dlm in their enviroment.
+# service that needs to have a dlm in their environment.
 function use_dlm {
     enable_service $(dlm_backend)
 }