Fix Python Linting Errors

Some idiot merged a commit with linting errors last night, this should
fix them.

Change-Id: Iab7e4a2a2d5311eba9a7ebbbd4a5f60ab8bf59fd

browbeat.py

@@ -68,7 +68,7 @@ def main():
 
     _logger.debug("CLI Args: {}".format(_cli_args))
 
-        # Default to all workloads
+    # Default to all workloads
     if _cli_args.workloads == []:
         _cli_args.workloads.append('all')
 

lib/Tools.py

@@ -136,7 +136,7 @@ class Tools(object):
             if item.startswith('$'):
                 var = item.translate(None, '$')
                 replacement = os.environ[var]
-                if replacement == None:
+                if replacement is None:
                     new_path.extend(item + "/")
                 else:
                     new_path.extend(replacement + "/")