Explicit parameter generation syntax in templates

- Add "generate" field to specify generator to be used
- Add "from" field to specify the input value for generator
- Remove "type" field, as it's always "string" anyway
Add kube api.Context to all API calls
Updated the HACKING.md with race and cover mode flags explained.
Merge pull request #192 from soltysh/hacking_cover

Merged by openshift-bot
Merge pull request #190 from pmorie/client

Merged by openshift-bot
switch to openshift-registry and add pullimages script
Merge pull request #181 from VojtechVitek/explicit_generators_syntax

Merged by openshift-bot
Merge pull request #189 from bparees/switch_registry

Merged by openshift-bot
Deployment Triggers POC

Adds DeploymentTriggerController and DeploymentConfigController and
fleshes out the deployments model.