Add _get function to base.Manager

This is useful so that we don't have to use _list in each Manager
subclass for getting a single resource and then fetching first item of
the array and checking for index error. This method wraps it for us.
Rack class

Currently just inherits from Resource and doesn't contain anything
testable really.
RackManager class
Merge pull request #1 from jistr/ftr/racks_python_api

Racks Python API and _get in base.Manager
Adds ResourceClass and ResourceClassManager (list, get)

ResourceClass just inherit from Resource now.
ResourceClassManager implement list and get methods.
Merge pull request #4 from petrblaho/ftr/resource-classes-get-list

Adds ResourceClassResource and ResourceClassManager (list, get)
Python API v1 entrypoint
Merge pull request #5 from jistr/ftr/python_api_entrypoint

Python API v1 entrypoint
Rename v1_0 module to v1

To be synced with Tuskar HTTP API versions.
Gitignore coverage temp files

Sometimes the coverage tool generates temp files like
`.coverage.f18-tuskar.21667.397772`. They are now gitignored.
Merge pull request #6 from jistr/bug/v1_module_name

v1 module name + minor gitignore change
Adds create method to ResourceClassManager

This is simplest implementation of create method
for ResourceClassManager
It just takes keyword arguments and pass them
to the _create method of base.Manager as a dictionary
Merge pull request #7 from petrblaho/ftr/resource-classes-create

Adds create method to ResourceClassManager
Add _single_path method for single resources path

It makes sure that resource id is not None, so that e.g. DELETE request
is not accidentally called on a collection URL.

Also _path method stub is now in base.Manager, to be overriden by child
classes.
Rack delete
Use _single_path in managers' get methods
Merge pull request #8 from jistr/ftr/rack_delete

Rack delete and safe _single_path helper
Adds delete method to ResourceClassManager

and adds test for that method
Merge pull request #9 from petrblaho/ftr/resource-classes-delete

Adds delete method to ResourceClassManager
Racks create and update