(#20548) Allow an array of resource titles to be passed into the ensure_resource function

This patch allows an array of resource titles to be passed into
the ensure_resource function.  Each item in the array will be
checked for existence and will be created if it doesn't already
exist.
Changed str-to-array conversion and removed abbreviation.
Refactor ensure_resource expectations

This splits out the ensure_resource expectations into separate
blocks for clarity.  Per adrienthebo's recommendation.
Terser method of string to array conversion courtesy of ethooz.
Merge pull request #152 from AlexCline/feature/master/allow_arrays_in_ensure_resource

(#20548) Allow an array of resource titles to be passed into the ensure_...