Ensure tiller is still running

There is an issue still where tiller doesn't seem to be initialized even though we have called initialize_tiller :

Example auto devops pipeline where it is dying https://staging.gitlab.com/hello-staging/minimal-ruby-app/-/jobs/36005680

$ auto-deploy initialize_tiller
Checking Tiller...
Tiller is listening on localhost:44134
Client: &version.Version{SemVer:"v2.14.0", GitCommit:"05811b84a3f93603dd6c2fcfe57944dfa7ab7fd0", GitTreeState:"clean"}
[debug] SERVER: "localhost:44134"

Kubernetes: &version.Info{Major:"1", Minor:"11+", GitVersion:"v1.11.10-gke.5", GitCommit:"5aa3a95d828fe45aab3611dfc4ebdc0341fe1507", GitTreeState:"clean", BuildDate:"2019-05-29T17:25:39Z", GoVersion:"go1.10.8b4", Compiler:"gc", Platform:"linux/amd64"}
Server: &version.Version{SemVer:"v2.14.0", GitCommit:"05811b84a3f93603dd6c2fcfe57944dfa7ab7fd0", GitTreeState:"clean"}

$ auto-deploy create_secret
Create secret...
$ auto-deploy deploy
secret "production-secret" deleted
secret/production-secret replaced
Error: could not find tiller
Deploying first release with database initialization...
Error: could not find tiller
Deploying second release...
Error: could not find tiller
deployment "production" successfully rolled out
$ auto-deploy delete canary
Error: could not find tiller
$ auto-deploy delete rollout
Error: could not find tiller
$ auto-deploy persist_environment_url

nohup the tiller so that it survives after the script terminates