Fix moto_server handling of unsigned requests
Fix moto_server handling of unsigned requests

Certain AWS requests are unsigned. Moto in standalone server mode
implements an heuristic to deduce the endpoint and region based on the
X-Amz-Target HTTP header. This commit extends this concept to add
additional endpoints that used unsigned requests at times.

spulec/moto,william-richard/moto,spulec/moto,william-richard/moto,william-richard/moto,whummer/moto,spulec/moto,whummer/moto,whummer/moto,william-richard/moto,spulec/moto,whummer/moto,william-richard/moto,whummer/moto,william-richard/moto,spulec/moto,spulec/moto,whummer/moto