Make the endpoints pattern configurable

This makes it possible to configure a url pattern and pass parameters to methods to build the url
Make the test more complicated

This makes a test more complex, and ensures that the URL is being correctly build.

The URL Pattern is being parsed (split by '/'), so it is wise to test that patterns containing two tokens per path item are parsed and built correctly.
Update README.md
Merge pull request #24 from kahnjw/configurable_urls

Configurable urls