Adding the ability to specify latitude and longitude from the command line when --location option is supplied.

I had the need to supply the latitude and longitude by hand, so I did some quick updates:
- Added `--latitude` and `--longitude` options (with shorthands `-A` and `-O`) to `update` and `reply` methods. These options are only used if `--location` is supplied.
- Updated the specs for `update` and `reply` so that the baseline case does not have `location` set.
- Added specs checking cases where:
   1. Just `location` is set.
   2. `location`, `latitude` and `longitude` are all set.