next: authentication support

[jdef]

we already have an auth API and implementation in master.

for reference, here's how things are proceeding in k8s-land: https://github.com/kubernetes/kubernetes/pull/23066/files

[jdef]

sounds like mesos default authn for HTTP V1 API will be to use Basic. pluggable mods in mesos can support other schemes. may be worth a two-pronged approach here:

1. implement support for basic
2. write a cgo wrapper that allows for reusing mesos authn modules as-is

[jdef]

basic http authn has been tested against mesos 1.0-rc1 and works as expected