review request for our nightly test infra

[Sean Busbey <bu...@apache.org>]

Hi folks!

Our Mike Drob reminded me this morning that the planned ASF Jenkins upgrade
that removes jdk7 support is this weekend. (old thread for details:
https://s.apache.org/FPJ5)

As mentioned in the thread, this will remove our ability to rely on the
current jdk7 nightly runs in branch-1.

I have the start of switching us to rely on Apache Yetus Test Patch's
nightly mode:

https://issues.apache.org/jira/browse/HBASE-18147

It has some room for improvement, but it gets us nightly runs based on the
same Docker configs we rely on for precommit and it properly reports jdk7
failures.

Could folks take a look? I'd like to have this in place by this evening so
that we can  get a jdk7 result before disabling our jdk7 builds this
weekend.