Point to permanent location by default for spec

[jisantuc]

Overview

This PR points to a specific release of the API spec by default, instead of whatever happens to be on
master.

It also removes the locally stored spec to avoid confusing people (and for fun!).

Testing

• ci
• initialize a client --

>>> from rasterfoundry.api import API
>>> client = API(api_token='your api token here')
>>> #or
>>> client = API('your refresh token here')

• if it succeeds, you're good

Closes #57

[notthatbreezy]

We can't delete the spec in the root of the repository until we communicate that current users need to upgrade the python client

Ok, I revived it.