Cluster Wide Operator

[ukclivecox]

• Single cluster wide operator to manage deployments in all namespaces
• Adds a flag in the helm chart to configure: single_namespace : true by default
• Updates Ksonnet scripts to handle single_namespace parameter
• Adds e2e tests for single namespace and clusterwide
• Adds units tests to Apife OAuth gateway

API endpoints are extended. For cluster wide and single name space:

• Ambassador endpoint at /seldon/namespace/deployment-name is added
• For OAuth gateway - extra key made of oauth-key + namespace is added

For cluster wide scenario only these endpoints will be used to ensure no ambiguity between deployments in each namespace.

Fixes #269