Add integration test to ensure URI's are requested as intended

[kadamwhite]

(For background see #89)

Superagent automatically converts multiple occurrences of the same query parameter key into array syntax: param=val&param=val becomes param[0]=val&param[1]=val. Because this behavior was not intuitive (other request libraries use the provided URL exactly as-is), we should add a test to verify that this behavior still occurs in case it changes in future versions of superagent.

[kadamwhite]

Updating issue based on a change of strategy in #89: The goal is to add some tests in which the responses of the HTTP requests are mocked, not the request library itself.

[kadamwhite]

Going to close this because basic integration test support has been added ( #123 #147 #148 #160 etc). It is not comprehensive but that will be an ongoing effort.