Remove usage of module py3kcompat

Module py3kcompat was removed from oslo-incubator. We need remove its
usage in client side firstly. This make us move smoothly when sync
oslo-incubator code.

Change-Id: I8b07c32c9852e747579a23685f3c8a07ac13ec01
Partial-Bug: #1280033
'name' should as be optional param on aggregate-update

'name' should be an optional parameter not required on aggregate-update,
so we can update 'availability_zone' only.

Change-Id: I23e669a3362e0bea44adc88744eed823ec1e7ebb
Closes-Bug: #1280118
Merge "Remove usage of module py3kcompat"
Revert "'name' should as be optional param on aggregate-update"

This reverts commit a2a1ef8f36644c3487bdaf00b2e70bcc6b948fb4.

Change-Id: I43bdc254e391c4b20254b8732c772fc9e728310c
Reopens-bug: #1280118
Partial-bug: #1281416