Update code style build task dependency: package was renamed
Do not manually encode parameters with array syntax (fixes #89)

superagent was transforming the (already-formatted)
    type[]=type1&type[]=type2
portion of the URL into
    type[][0]=type1&type[][1]=type2

This syntax is invalid, and results in an error on the WP side.

By removing the prepareParameters method, we eliminate all of our custom
handling for array syntax, and trust that superagent will take care of it.

TODO: Add a test suite to verify this integration point.
Simplify query string generation with the "qs" module

qs is the same module used to parse URLs within Superagent, so using it
here provides a more robust solution to the issue of indexed array syntax:
instead of planning for the request library to transform our URI in a
particular way, format our URI in that manner to begin with so that no
further transformation occurs.

The `prepareFilters` and `generateQueryString` methods were removed: their
behavior is replicated more simply using qs.