Update copyright year in docs to 2017.

Author: mbogosian

docs/conf.py

@@ -54,7 +54,7 @@
 
 # General information about the project.
 project = u'Dropbox for Python'
-copyright = u'2016, Dropbox, Inc.'
+copyright = u'2017, Dropbox, Inc.'
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the