This patch allows a local JSON file to specify a local path
in the JSON object of a Resource, through the "url" field.
Local paths can be entered with the prefix "file:" in "url".
All File URI scheme formats are supported.
This behavior is the same as using specific Resource classes
(ex. BinaryResource) and passing a local_path into the function.
But, the above infrastructure does not allow simultaneous
creation of Resources and Workloads of those Resources.
With this patch, someone can use a local JSON, specify the location
of local Resources and create a Workload from those Resources and
test both together.
Also, this patch adds pyunit tests to check the functionality
of the function used to convert the "url" field into a path.
Change-Id: I1fa3ce33a9870528efd7751d7ca24c27baf36ad4
