f8-arq needs to be able to configure ImageStreamTag namespace

DeploymentConfigs created in a fabric8-arquillian test references an ImageStreamTag of the current test namespace, e.g.:

  triggers:
  - type: ConfigChange
  - imageChangeParams:
      automatic: true
      containerNames:
      - spring-boot
      from:
        kind: ImageStreamTag
        name: spring-boot-webmvc-archetype:1.0
        namespace: maschmid-test
    type: ImageChange

As the test usually runs in a different namespace to the one the image were originally built, the test need to modify the namespace to point to the namespace in which these image streams exists (which cannot be guessed, user needs to specify this somehow).

(This is specific to the openshift mode / s2i strategy, as otherwise the f8-arq just references images, which are globally available (or at least it is assumed that both the build and test can access the same docker registry))