deprecated feature parity with libmesos

[spacejam]

libmesos has a grace period during which it will try to support the API from the last version, in order to support graceful cluster upgrades.

libmesos-based mesos cluster upgrade story from mesos master version X -> Y:

1. ensure that all slave+executor+scheduler processes are running on top of libmesos version X or Y
2. upgrade a mesos master to version Y, bounce it, restart the other HA masters (still running X) so that leadership passes to the master on version Y
3. observe cluster health metrics, being on high-alert to turn off the new master if things get wonky so that a master on the old version will take over
4. after suspicion fades, upgrade and bounce the other HA masters from X to Y
5. gradually move all slave+executor+scheduler processes over to version Y, before upgrade Y->Z happens

mesos-go based cluster upgrade story:

1. restart everything as fast as you can, because there is no graceful transition possible, eating a guaranteed maintenance window of unavailability
2. hope in your heart of hearts that nothing bad happens while nervously staring at the health metrics - meanwhile every second you are losing money and customer trust

Furthermore, many users of mesos-go have no idea that it behaves differently from what they're used to with libmesos! mesos-go needs to make this super explicit up-front, because outages are probably already happening due to this mismatch of assumptions!

[spacejam]

This will benefit significantly from an automated test matrix, for instance the 0.23.0 branch should have basic tests that run against each of the 16 combinations ({0.23.0,0.22.0} X {master, slave, executor, scheduler}).

[tsenart]

So the gist of this issue is to transition to enable a Mesos cluster upgrade story identical to libmesos, with mesos-go.

[tsenart]

By @spacejam in #165

Problem: I'm running mesos version X. What git SHA should I be using?
Initially, I'd like to see a tag for:
0.22.0
0.23.0 (after #159 is merged in and more testing is performed)
new versions after they have been properly tested

[jdef]

hopefully this will be easier to do once Mesos v1 APIs land in master