Switch to using Go modules.
This migrates our vendor.json to use Go 1.11's modules system, and
replaces the vendor folder with the output of go mod vendor.
The vendored code should remain basically the same; I believe some
tree shaking of packages and support scripts/licenses/READMEs/etc.
happened.
This also fixes Travis and our Makefile to no longer use govendor.
Update all the packages under google.golang.org/api to use the same
commit. This is a necessary precursor for using Go modules.
There is a breaking API change in the clients, but it's a one line
change. As such, Travis will say this doesn't build. I've verified after
the one line change, it will run the unit tests. That change needs to be
made in MM, however. Once this PR is merged, a PR against MM will be
opened.
Update all the packages under google.golang.org/api to use the same
commit. This is a necessary precursor for using Go modules.
There is a breaking API change in the clients, but it's a one line
change. As such, Travis will say this doesn't build. I've verified after
the one line change, it will run the unit tests. That change needs to be
made in MM, however. Once this PR is merged, a PR against MM will be
opened.
