README.md doesn't work as written, base_url needs to have /api/ appen…

[steverhoades]

…ded.

Ran into an issue based on README, the error was:

  Client error response [url] http://127.0.0.1:8000/oauth/v2/token [status code] 404 [reason phrase] Not Found  

Appending '/api/' to the base_url fixes it.