Adding Ash Install to Provision

Adding Ash install capability from cr/2966529.
Also added tests and reloaded mocks.

BUG=None
TEST=unit

Change-Id: I5124d7fa25b35d9096423851ad1ddb5c3e21ce4e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/3021806
Reviewed-by: C Shapiro <shapiroc@chromium.org>
Tested-by: Jaques Clapauch <jaquesc@google.com>
Tested-by: C Shapiro <shapiroc@chromium.org>
Auto-Submit: Jaques Clapauch <jaquesc@google.com>
Commit-Queue: C Shapiro <shapiroc@chromium.org>
8 files changed