This commit fixes getting MAC address while inspection for iRMC driver.
To remove ord() in retrieving MAC address, it can avoid the following
exception:
TypeError: ord() expected string of length 1, but int found
Also, this commit sets the following type of mock for UT. So, I add
'pysnmp'[1] into test-requirements.txt and lower-constraints.txt.
* pysnmp.proto.rfc1902.OctetString
* pysnmp.proto.rfc1902.Integer32
[1] https://bit.ly/3bDeTCH
Change-Id: I1e013a93854e01a7060e1fc48aac091e7e9b74cb