[autotest] Convert ssh connectivity checks to the new verify.
This adds initial code to use the new verification framework.
The conversion only affects CrosHost (and its subclass MoblabHost),
and introduces only two verifiers:
* SshVerifier checks ssh connectivity. This replaces
AbstractSSHHost.verify_connectivity(), but only for CrosHost and
its subclasses.
* CrosHostVerifier is a stepping stone that provides all other
verification steps by calling the existing verify methods
in CrosHost.
BUG=chromium:586317,chromium:586326
TEST=Run various test cases against a local instance
Change-Id: I2b09117d3da9699e54038320a9809ba72a44e6e7
Reviewed-on: https://chromium-review.googlesource.com/327279
Commit-Ready: Richard Barnette <jrbarnette@chromium.org>
Tested-by: Richard Barnette <jrbarnette@chromium.org>
Reviewed-by: Kevin Cheng <kevcheng@chromium.org>
3 files changed