Add a uri_join_paths helper function and tests

The standard URI::join method is not intended for joining URI relative
path segments. This function merely helps to accurately join supplied
paths. While the objective should be to use the OpenStack python
clients for much of the URL wrangling, there may still be times when
joining paths may be necessary.

All tests passing.

Change-Id: I39fe37b2b15ed05701d928065e6d70109634a382
Add a new PrettyTable parsing function

The current state of (at least some) OpenStack CLI tools do not provide a
mechanism for outputting data in formats other than PrettyTable output.
Therefore this function is intended to parse PrettyTable output into a
usable array of hashes. Similarly, it will flatten Property/Value tables
into a single element array.

This change adds a parser as well as the associated rspec tests for that
parser. The initial use case for this function is to allow the Identity
LWRP to replace HTTP/S calls with Identity CLI calls. As much of what
happens with the CLI involves chaining UUIDs, this function is critical
to make that happen.

Note well: bumping the version of this cookbook to 0.2.1

All tests pass.

Change-Id: Icac7fcd1670f3240d59b07fce25cf8283ba2e0d8