Bump to 7.1.0.

Not using 7.0.0 because it was published for a short amount of time
and was a bad release.

Author: braincore

dropbox/dropbox.py

@@ -4,7 +4,7 @@
     'create_session',
 ]
 
-__version__ = '6.9.0'
+__version__ = '7.1.0'
 
 import contextlib
 import json