Description of problem:
After providing MigCluster connection details, CAM hits a "Reconcile failed" error shown on the MigCluster due to:"error":"strconv.Atoi: parsing \"\": invalid syntax"

This problem arises on clusters where k8s major/minor versions are not filled out in the k8s `/version` endpoint

Response Body: {
  "major": "",
  "minor": "",
  "gitVersion": "v1.9.1+a0ce1bc657",
  "gitCommit": "a0ce1bc",
  "gitTreeState": "clean",
  "buildDate": "2018-04-26T16:48:23Z",
  "goVersion": "go1.9.4",
  "compiler": "gc",
  "platform": "linux/amd64"
}


Version-Release number of selected component (if applicable):
CAM v1.2.0
OCP 3.9.27 (other OCP 3.9 versions also affected)

How reproducible:
Always, on select OCP 3.9 clusters where kube major/minor versions aren't available (known to fail on OCP 3.9.27)

Steps to Reproduce:
1. Install CAM 1.2.0
2. Go to web UI (CLI also works) 
3. Set up a MigCluster ("Cluster" in web UI) using connection details of an OCP 3.9.27 cluster
4. Verify that error condition is raised on MigCluster due to reconcile failure. Error message will mention "atoi" conversion.

Actual results:
Reconcile failed on MigCluster, blocks all other actions on this MigCluster

Expected results:
Reconcile works as expected on MigCluster, migrations can be performed


Additional info:

This is a known issue with some OCP 3.9 versions: https://github.com/openshift/origin/pull/19731 

We are developing a fix to overcome the missing major/minor version fields by instead parsing gitVersion, which appears to still be available on OCP 3.9 clusters missing the major/minor fields.