fixes key error when using version and account usage calls

When using the get_version() method, we were getting an error on line 1422 - "r" isn't a list except on an /account/usage call, so checking "r[0]" on a dict was breaking.

Solution: re-order the elif statements so the /account/usage case is checked last, and also add an isinstance() check on whether or not "r" is a list.