Clean up, add role, and vendor hack.

Some basic cleanups, addition of passing in role if needed for ACLs on mesos side, and hack to vendored mesos-go code to ignore InverseOffersMessage messages because they are causing a panic. Really just need mesos-go to be released with compatibility with mesos v1.0*.

v1.2.0

Switching to Stop() so that our framework will try to unregister if c…

v1.1.5

No longer exits if received offer rescinded. This is similar behavior to Marathon and Rendler.

v1.1.4

Adding log output on every setup of a task to namely figure out the h…

v1.1.3

Don't exit when slave lost because it may not be our tasks' slave.

Exit was added because it was thought it caused the program to hang and
consume resources in mesos otherwise. This is not the case as later
commits show that printLogs() was actually causing the process to block
and then ResourceOffers() was consuming for really an unknown reason :/.

This change has been tested to be safe (not consume all mesos resources)
when:

* Random slaves are lost in cluster.
* Slave the task is running on is lost.
* Slave the task is running on becomes "unhealthy" (simulated with
  iptables).

v1.1.2

Fixing when mesos-agent is unreachable for log fetching.

If we couldn't get the logs from the agent, it would block inside the
case <-timer select making the main thread not be able to handle
messages sent to StatusUpdate nor ResourceOffers resulting in consuming
the entire cluster :(. This is a stop gap until I figure out how to
properly fix this.

v1.1.1

Will exit if framework gets offer rescinded or slave lost from mesos.

v1.1.0

Release of

• General cleanup of code with more comments.
• JSON interface for config / passing in task to runonce. See example-config.json and pass it in via -config=example-config.json

v1.0.6

Fixing exit 0 always.

v1.0.5

More logging bugfixes to better stream back stderr/out from mesos when tasks fail or get killed.