heat-client command doesn't output a valid JSON

Issue

• CLI command heat output-show is used to display the output of a given stack. The output is available in 2 formats: JSON and RAW.
• On Openstack versions 8,9 and 10, when executing the command with 'JSON' output option, the output isn't displayed as a valid 'JSON' format as expected.
• Example:

[stack@undercloud ~]$ heat output-show -a -F json overcloud
"58a08a1b-20c5-49f4-b216-37d8e7159c6a"
"823963f9-aed9-4c3e-86c6-37d1f8a80d2d"