Catch ProcessExecutionError in revoke_cert

Catch processExecutionError if revoking the
certificate fails.

This change has been abandoned by Chuck Short, so
I am continuing where he left off (mattoliverau).

Continues abandoned change: 17741

Change-Id: I9714ea8cece87256ff5f9a936286c1da3d628af9
Closes-Bug: #883320
Co-Authored-By: chuck.short@canonical.com
Drop support for scheduler 2.x rpc interface

In commit 741661a6695ccc56e5f50c4d85954cd3ed9ebda5, a part of
Icehouse, we added support for the 3.x interface.  Now that Juno
development is open, we can drop support for the old 2.x API.

For more information on this change, see:

    https://wiki.openstack.org/wiki/RpcMajorVersionUpdates

UpgradeImpact

Change-Id: I7bfad51ae46e999b30e003a5a5c7e341461dba02
Add API schema for v2.1/v3 aggregates API

By defining the API schema, it is possible to separate the validation
code from the API method. The API method can be more simple.
In addition, a response of API validation error can be consistent for
the whole Nova API.

Partially implements blueprint v3-api-schema

Change-Id: I67a1b723f37256e8bdfaf38d9f5ad0a4c4d2e53e
Merge "Catch ProcessExecutionError in revoke_cert"
Merge "Add API schema for v2.1/v3 aggregates API"
Merge "Drop support for scheduler 2.x rpc interface"