Extend openstack_command
Extend openstack_command

This patch extends openstack_command to accept an array in addition to a
string as an argument.

This allows the use of openstack_command in cases where an argument
contains protected spaces.

Examples:

mistral execution-create my_workflow \
    '{"names": ["John", "Mistral", "Ivan", "Crystal"]}'

barbican secret list --name chef_test_secret --format value -c"Secret href"

Without this patch, all arguments have to be passed as a single string
which openstack_command splits on white space regardless of any
quotation marks. Therefore, the examples above will fail.

Change-Id: I0419a1526beb103839a3cf235eba6c41d9d946d5
Closes-Bug: #1723949

openstack/cookbook-openstack-common,openstack/cookbook-openstack-common