Convert all response values to a string
Convert all response values to a string

Although RestClient::Response acts like a string, it raises a warning
if #to_i is called on it, such as by our own Util.to_numeric (since
RestClient::Response used to have behavior of returning an HTTP status
code). We now start with response values as strings for less
confusing processing by clients.

ianfleeton/paypal-express