FPR4100: Hitless upgrade of FXOS and ASA, using FXOS cli (2017)

See how to perform a hitless upgrade on a pair of FXOS FPR4100s running ASA app in active/standby failover. We monitor connectivity through ASA failover pair and go through upgrading secondary/standby unit first, then switch active state to upgraded unit, before upgrading primary/standby FPR4100.