When output to shell, the token issue time is fine; however when
selecting the json formatter (via the --format json) option, an
exception is raised when formatting the dataetime data.
Rather than pass in the datetime data, we should format the data
with the ISO 8601 formatting.
Closes-Bug: 1619937
Change-Id: Iffebb2d5413fabfd283dfa94fc560fc37270f9dd