cluster up: optionally install metrics components

[csrwng]

Adds an experimental flag to oc cluster up to install metrics components.

When specifying the --metrics flag, the master asset config is updated with the hostname for the metrics route and the pod to deploy metrics components is created.

[csrwng]

@smarterclayton ptal
/cc @jwforres @spadgett

[csrwng]

Opened the following issues on origin-metrics:
openshift/origin-metrics#148 - Reduce memory footprint
openshift/origin-metrics#149 - Heapster not collecting metrics on docker machine OS

[smarterclayton]

Why are you using a generate name?

[csrwng]

Hadn't given it much thought. The original template has a generate name. But in my case, I guess it doesn't make much sense. I'll switch it to a regular name.

[smarterclayton]

No other comments beyond that.

[csrwng]

Comment addressed.

Also added a line with the metrics URL in the info part when you specify the --metrics flag:

-- Server Information ...
   OpenShift server started.
   The server is accessible via web console at:
       https://192.168.56.1:8443

   The metrics service is available at:
       https://metrics-openshift-infra.192.168.56.1.xip.io

   You are logged in as:
       User:     developer
       Password: developer

   To login as administrator:
       oc login -u system:admin

[smarterclayton]

LGTM [merge]

[openshift-bot]

continuous-integration/openshift-jenkins/merge SUCCESS (https://ci.openshift.redhat.com/jenkins/job/test_pr_origin/4903/) (Image: devenv-rhel7_4382)

[openshift-bot]

Evaluated for origin merge up to 141cc0f

[openshift-bot]

[Test]ing while waiting on the merge queue

[openshift-bot]

Evaluated for origin test up to 141cc0f

[openshift-bot]

continuous-integration/openshift-jenkins/test SUCCESS (https://ci.openshift.redhat.com/jenkins/job/test_pr_origin/4903/)