This is the 2nd attempt. The previous was reverted while we figured out
the regional mirrors (oops).
New plan: k8s.gcr.io is a read-only facade that auto-detects your source
region (us, eu, or asia for now) and pulls from the closest. To publish
an image, push k8s-staging.gcr.io and it will be synced to the regionals
automatically (similar to today). For now the staging is an alias to
gcr.io/google_containers (the legacy URL).
When we move off of google-owned projects (working on it), then we just
do a one-time sync, and change the google-internal config, and nobody
outside should notice.
We can, in parallel, change the auto-sync into a manual sync - send a PR
to "promote" something from staging, and a bot activates it. Nice and
visible, easy to keep track of.
Automatic merge from submit-queue (batch tested with PRs 41812, 41665, 40007, 41281, 41771)
Bump golang versions to 1.7.5
**What this PR does / why we need it**: While #41636 might not make it in until 1.7, this would bump current golang versions from 1.7.4 to 1.7.5 to integrate the fixes from that patch version. This would include, among other things, a fix to ensure cross-built binaries for darwin don't have certificate validation errors (golang/go#18688)
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: none
**Special notes for your reviewer**:
**Release note**:
```release-note
Upgrade golang versions to 1.7.5
```