Add issued handlers to auth_ref and fixtures

issued_at is a standard part of V2 and V3 tokens so add it to
AccessInfo in a similar way to expiry. Also it should be included when
generating tokens so include it in fixtures.

Change-Id: I0d62d8ce6472466886751e10e98046b8e398e079
Correcting using-api-v2.rst

Changes
* removed extraneous word from Introduction section

Closes-Bug: #1334915
Change-Id: I201ddb70a4d91e0d615e322abc43848993dee573
Updated from global requirements

Change-Id: Ibb290d0f2d616b7730914bfc829a7f555ba0b688
Merge "Add issued handlers to auth_ref and fixtures"
Merge "Correcting using-api-v2.rst"