Should fix messages like this from the Travis builds:
```
Daily bandwidth rate limit exceeded for IP 52.0.240.122.
```
Refs https://github.com/golang/go/issues/12933
* Remove `make updatedeps` from Travis build. We'll follow up with more
specific plans around dependency updating in subsequent PRs.
* Update all `make` targets to set `GO15VENDOREXPERIMENT=1` and to
filter out `/vendor/` from `./...` where appropriate.
* Temporarily remove `vet` from the `make test` target until we can
figure out how to get it to not vet `vendor/`. (Initial
experimentation failed to yield the proper incantation.)
Everything is pinned to current master, with the exception of:
* Azure/azure-sdk-for-go which is pinned before the breaking change today
* aws/aws-sdk-go which is pinned to the most recent tag
The documentation still needs to be updated, which we can do in a follow
up PR. The goal here is to unblock release.
I don't really see a good reason for running a build against Go tip.
This probably made more sense in the earlier days of Golang, but now
IMHO it's just wasting cycles for not much benefit.
/cc @jen20 @mitchellh
Christoph Blecker