Faraday dependency minimum should be 1.0

[matt-eaton]

Not sure what is involved in setting a minimum dependency for Faraday. I think this line here: https://github.com/sparkapi/spark_api/blob/0c8b5df40c5c12dca4c311ba38f01a8e7afd9cf1/lib/spark_api/faraday_middleware.rb#L33

Will require Faraday 1.0.

This looks like the PR into the 1.0 release that adds the functionality to support "request_body".

https://github.com/sparkapi/spark_api/blob/0c8b5df40c5c12dca4c311ba38f01a8e7afd9cf1/lib/spark_api/faraday_middleware.rb#L33