Serverless deploy error "no token in bearer response"
### Summary
Deployment of our [Knative Ruby App](https://gitlab.com/knative-examples/knative-ruby-app) fails at the `deploy` stage using all default settings as outlined in [this documentation](https://docs.gitlab.com/ee/user/project/clusters/serverless/).
### Steps to reproduce
1. Fork our Knative Ruby App project or clone the files into a new repository.
2. Set up a Kubernetes cluster and integrate it with GitLab.
3. Install Helm Tiller.
4. Install Knative and provide it with a domain name.
5. Direct a wildcard A record to the IP address provided by Knative.
6. Run a pipeline.
7. Observe the error message in the job log (example below).
### Example Project
This was reproduced in [this project](https://gitlab.com/tristan/kube-kube-kube).
- [Example failed pipeline](https://gitlab.com/tristan/kube-kube-kube/pipelines/47598089)
### What is the current *bug* behavior?
Currently, the app is not able to be deployed due to an error in the `deploy` stage. The `build` stage encounters no issues.
### What is the expected *correct* behavior?
That the app is deployed to the cluster sucessfully and an entry appears in the `Serverless` section of the project.
### Relevant logs and/or screenshots
Output of the job log for the `deploy` stage showing the error.
```
Running with gitlab-runner 11.8.0-rc1 (7a7b8375)
on docker-auto-scale 0277ea0f
Using Docker executor with image gcr.io/triggermesh/tm@sha256:e3ee74db94d215bd297738d93577481f3e4db38013326c90d57f873df7ab41d5 ...
Pulling docker image gcr.io/triggermesh/tm@sha256:e3ee74db94d215bd297738d93577481f3e4db38013326c90d57f873df7ab41d5 ...
Using docker image sha256:6b3f6590a9b30bd7aafb9573f047d930c70066e43955b4beb18a1eee175f6de1 for gcr.io/triggermesh/tm@sha256:e3ee74db94d215bd297738d93577481f3e4db38013326c90d57f873df7ab41d5 ...
Running on runner-0277ea0f-project-10060955-concurrent-0 via runner-0277ea0f-srm-1550181942-eccf4d7f...
Cloning repository...
Cloning into '/builds/tristan/kube-kube-kube'...
Checking out 692997e7 as master...
Skipping Git submodules setup
$ echo "$CI_REGISTRY_IMAGE"
registry.gitlab.com/tristan/kube-kube-kube
$ tm -n "$KUBE_NAMESPACE" --config "$KUBECONFIG" deploy service "$CI_PROJECT_NAME" --from-image "$CI_REGISTRY_IMAGE" --wait
Deployment started. Run "tm -n kube-kube-kube-10060955 describe service kube-kube-kube" to see the details
Waiting for ready state.2019/02/14 22:07:51 Revision "kube-kube-kube-00001" failed with message: "no token in bearer response:\n{\"errors\":[{\"code\":\"DENIED\",\"message\":\"access forbidden\"}],\"http_status\":403}".
ERROR: Job failed: exit code 1
```
### Output of checks
This bug happens on GitLab.com
#### Results of GitLab environment info
GitLab.com 11.8.0-rc4-ee
It was suggested in [this](https://stackoverflow.com/questions/54607831/gitlab-serverless-deployment-fails-due-to-no-token-in-bearer-response) SO question that the image defined in the `deploy` stage may be the issue. However, a change to that leads to [a different error](https://stackoverflow.com/questions/54609664/gitlab-serverless-deployment-fails-due-to-nil-watch-interface?noredirect=1&lq=1).
/cc @danielgruesso
ZD (Internal): https://gitlab.zendesk.com/agent/tickets/114285
issue