Fix deprecation warnings due to invalid escape sequences.

Author: tirkarthi

libtmux/common.py

@@ -233,7 +233,7 @@ def __init__(self, *args, **kwargs):
 
 class TmuxMappingObject(MutableMapping):
 
-    """Base: :py:class:`MutableMapping`.
+    r"""Base: :py:class:`MutableMapping`.
 
     Convenience container. Base class for :class:`Pane`, :class:`Window`,
     :class:`Session` and :class:`Server`.

libtmux/pane.py

@@ -153,7 +153,7 @@ def clear(self):
     def reset(self):
         """Reset and clear pane history. """
 
-        self.cmd('send-keys', '-R \; clear-history')
+        self.cmd('send-keys', r'-R \; clear-history')
 
     def split_window(self, attach=False, vertical=True, start_directory=None):
         """