Fixes#2889.
VA now implements two gRPC services: VA and CAA. These both run on the same port, but this allows implementation of the IsCAAValid RPC to skip using the gRPC wrappers, and makes it easier to potentially separate the service into its own package in the future.
RA.NewCertificate now checks the expiration times of authorizations, and will call out to VA to recheck CAA for those authorizations that were not validated recently enough.
Updates the various gRPC/protobuf libs (google.golang.org/grpc/... and github.com/golang/protobuf/proto) and the boulder-tools image so that we can update to the newest github.com/grpc-ecosystem/go-grpc-prometheus. Also regenerates all of the protobuf definition files.
Tests run on updated packages all pass.
Unblocks #2633fixes#2636.
Protobuf files need to be regenerated because (I think) Golang 1.7.3 uses a somewhat different method of ordering fields in a struct when marshaling to bytes.
The `letsencrypt/boulder-tools` image was recently updated, pulling in version
0.8.0 of certbot. That version stores the output of `certonly` requests in a
different path. In test.sh, we check out a specific tagged release of certbot in
order to get its integration tests. Prior to this commit, we were using
certbot 0.8.0 with the integration tests from version 0.6.0 of certbot,
which looked for `certonly` output in the wrong place, and failed.
This commit changes test.sh to checkout the 0.8.0 branch, and also removes a
temporary shim we used to make the `certbot` command call out to the
`letsencrypt` command.
Also, since the latest version of `letsencrypt/boulder-tools` includes an updated
`protoc-gen-go`, this change also updates the support packages to match.
Jacob Hoffman-Andrews