Updated testFT-SAE-roam to use the TestContext APIs as well as
fixed the failure which was introduced after requiring stricter
AKM logic for SAE networks. The new failure was due to the hostapd
config not including the standard SAE AKM which is actually
required by the spec.
This test was copied from testFT-PSK-roam, but for SAE. The test behaves
as follows:
- Connect to SAE network (full authentication)
- Fast transition to another SAE AP
- Fast transition to a PSK/WPA2 AP
