If the supplied path is not of the form /v1/a/c/o then
swift tempurl subcommand will now return an error message.
Also removes redundant check for seconds parameter being an int
from shell.py because the same check is made when calling
utils.generate_temp_url.
Drive-by fix for missing param definition for generate_temp_url.
Change-Id: I41f4389948b01fadaa5fc4939ea12e0ed2167345
Related-Change: I0fb2ce125fe12d660e4deb778265016bdd5ff31b