Make etcd a preinstall dependency

[morgo]

This changes the bootstrap, so I've verified with:

make docker_bootstrap && make docker_test flavor=mysql57

We will need to update the documentation to say that etcd should be pre-installed, similar to mysql-server. I have PRs in progress for it under both the local guide and the contributing guide: vitessio/website#316
vitessio/website#309

The motivation here is that if something is reliably available in repos, we should get out of the business of managing it - there could be vulnerabilities, failures in the install process, etc.

Signed-off-by: Morgan Tocker tocker@gmail.com

[deepthi]

Docker tests should be run with-pull=false to use the local image, otherwise the image is pulled from dockerhub. There doesn't seem to be a way to pass this to make docker_test, it always pulls the image.
The alternative way of doing that is to do go run test.go -pull=false. Flavor defaults to mysql57.

[morgo]

I am running go run test.go -pull=false now. The prepared statements test may fail, since it fails for me in master after a new bootstrap, but I'll verify no other tests fail.

[morgo]

It looks like etcd is not available in Debian Stretch (2017), so this patch won't work as planned :( I am going to close it for now, and re-evaluate when we migrate the test suites to Golang. This will help us bump the base-image OS.