Update debug_statement_hook.py

Adds celery rdb as debugger: http://docs.celeryproject.org/en/latest/tutorials/debugging.html
diff --git a/pre_commit_hooks/debug_statement_hook.py b/pre_commit_hooks/debug_statement_hook.py
index 8e02480..52fe72e 100644
--- a/pre_commit_hooks/debug_statement_hook.py
+++ b/pre_commit_hooks/debug_statement_hook.py
@@ -7,7 +7,7 @@
 import traceback
 
 
-DEBUG_STATEMENTS = set(['pdb', 'ipdb', 'pudb', 'q'])
+DEBUG_STATEMENTS = set(['pdb', 'ipdb', 'pudb', 'q', 'rdb'])
 
 
 DebugStatement = collections.namedtuple(