Log Message:
Updated py-click to 6.7.

Version 6.7
-----------

(bugfix release; released on January 6th 2017)

- Make `click.progressbar` work with `codecs.open` files. See #637.
- Fix bug in bash completion with nested subcommands. See #639.
- Fix test runner not saving caller env correctly. See #644.
- Fix handling of SIGPIPE. See #626
- Deal with broken Windows environments such as Google App Engine's. See #711.