This change adds UpdateService resource and SimpleUpdate action to
sushy-tools. The goal behind this addition is enabling support for
automated testing of firmware update functionality in virtualized
environments. Note: no actual firmware update is performed with these
API calls, the only result is incrementing the BiosVersion value stored
in instance metadata.
Change-Id: I22d9b7614a5a7243e08d40392a0a49a31ee00034