Make the kubernetes namespace accessible in the dev container

[rberrelleza]

Is your feature request related to a problem? Please describe.
A lot of dev scripts need to know the namespace they are running as (e.g. kubeapps uses it on their js code to validate acccess)

Describe the solution you'd like
Inject a "env context" into my dev container with the namespace.

Describe alternatives you've considered
I can add this to my deployment, but I feel that adding a value only consumed by dev on a manifest that's going to go to prod creates noise and potential issues

[rberrelleza]

Fixed by #129