Correct some typos

During my review of the project, I corrected these typos
to make it more clear. If we will generate docs based on
the code, this will help.

Change-Id: Iee3d9210431e0489c4872637fe04409fe0addc0e

senlinclient/common/sdk.py

@@ -27,9 +27,9 @@ prop = base.prop
 
 
 class ProfileAction(argparse.Action):
-    """A custom action to parse user proferences as key=value pairs
+    """A custom action to parse user preferences as key=value pairs
 
-    Stores results in users proferences object.
+    Stores results in users preferences object.
     """
     prof = profile.Profile()
 

senlinclient/v1/client.py

@@ -222,7 +222,7 @@ class Client(object):
         return self.service.cluster_scale_in(cluster, count)
 
     def cluster_policies(self, cluster, **queries):
-        """List all policies attached to clusdter
+        """List all policies attached to cluster
 
         Doc link:
         http://developer.openstack.org/api-ref-clustering-v1.html

tools/senlinrc

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-# IMPORTANT: Cleanse existing environment varible first
+# IMPORTANT: Cleanse existing environment variable first
 unset OS_USERNAME
 unset OS_PASSWORD
 unset OS_REGION_NAME