Revert "Revert "Updated provision-ecommerce script to include new parameter which will be required for building ecommerce site specific urls for discovery service.""

This reverts commit fdd4889d.

Similar to "make stop", "make down" is now continues when
docker-sync doesn't exist (e.g. on Linux)

Revert "Updated provision-ecommerce script to include new parameter which will be required for building ecommerce site specific urls for discovery service."

This reverts commit 97027ad9.

required for building ecommerce site specific urls for discovery
service.

LEARNER-1135

clone to save space

https://blog.travis-ci.com/2017-06-21-trusty-updates-2017-Q2-launch
https://github.com/travis-ci/build-environment-updates/blob/master/2017Q2/gce/garnet-trusty/dpkg-manifest.diff

The configuration changes for the Discovery Service are now on the master branch of edx/configuration. There is no longer a need for a separate tag.

LEARNER-1375

This partially reverts commit 9b3b738a.

Further profiling showed that LMS/Studio startup times about tripled
when we dropped Docker Sync in favor of Docker's built in cached volume
mount system (going from 7-8s to anywhere betwen 22-28s). So we're
rolling back the part of that commit that removed Docker Sync and the
recommendations in the README.

However, we still want to keep the minimum version at 17.05 Edge, for
image building purposes. We also want to clarify that we did try using
Docker's built in cached volume support, so that people don't waste
time trying it again until Docker really implements "delegated" mode.