The database returns an array of key-value strings like `"k1=eq.hello
world"`. Haskell URL-encodes the portion after the equal sign and joins
them with `&`.
Includes updates to tests in Feature.InsertSpec: The CompoundPK has been
modified to have one Int and one String. We attempt to add a key with a
String that has spaces and other special characters. This requires that
the returned Location header is properly URL-encoded.
