Pulp

Revision f4459998

Updates saving behaviors of `ProgressReport`

The context manager now provides saving in all cases.
Also the docstrings have been updated to make this
behavior clear to the user.

Also the short form of `ProgressBar` was fixed
to create the 'pb' variable within the 'with'
section.

https://pulp.plan.io/issues/2092
re #2092