Rather than always generating a new key, let's sometimes recycle a key
value to test caching.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
So we can test what happens if the Serial library has an error. I also
make exceptions less likely to happen.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The simulator fakes up some libraries so that the main door controller
script can be tested without needing a Raspberry Pi.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>