- Will be used for upcoming test for end-to-end HTTP/2 routing
- Serves h2c (HTTP/2 over cleartext) traffic and will error if sent non
HTTP/2 traffic

[cloudfoundry/routing-release#200]

Co-authored-by: Greg Cobb <gcobb@vmware.com>

- Add new suite for HTTP/2 CATs
- Currently passing using spike from
  cloudfoundry/routing-release#200 (comment)
- Likely to change with full implementation
- Extract `GetRouteGuid` v3 helper from multiple_app_ports test

[cloudfoundry/routing-release#200]

Co-authored-by: Carson Long <lcarson@vmware.com>
Co-authored-by: Belinda Liu <lbelinda@vmware.com>

- Includes a new gRPC test app
- Updates vendor with dependencies needed for making gRPC requests
- Currently proto files are copied into the helpers directory from the
assets/grpc/test directory as a work-around to import issues.
- This test will only pass on environment that have true end-to-end
HTTP/2 (including load balancer ingress and egress). Be careful.

[cloudfoundry/routing-release#200]

Co-authored-by: Greg Cobb <gcobb@vmware.com>

These tests were previously written against a spike implementation. We
now have a complete implementation with a slightly different field on
the API to configure end-to-end HTTP/2 for route destinations.

[cloudfoundry/routing-release#200]

Co-authored-by: Michael Oleske <moleske@vmware.com>

- HTTP/2 test suite was no longer passing due to incorrect start
commands. Not sure if this was due to a change in the golang buildpacks.
- Fix by removing explicit start commands from `cf push` in HTTP/2 tests
- Unify pattern for how we push the HTTP/2 and gRPC sample apps
- Update gRPC go.mod file

[cloudfoundry/routing-release#200]

Authored-by: Greg Cobb <gcobb@pivotal.io>