Automation scale and run tests

- Porting run tests from python to go spec.
- Adding scale up to 3, 5 and 10 scale tests.
- Removing python CI scripts from executing.

Add ability to provide imagePath in Riofile

Move to go testing

Use of kubectl instead of an alias

fix typo

In order to onboard devs and the community faster we are unifying
the codebase into go. We are also moving towards BDD style specs so
that the tests are more human readable, and our current suite (and its
gaps) are more immediately obvious.

Update README with slack info

Update readme for slack info

README update: route insert is a flag on add, not standalone

Doc changes for v0.5.0

Switch ingress to extension api

Fix wrong mixer naming

Swap name and namespace in router docs

Fix lite install being broken in istio mesh mode

Fix lite install paramaters being broken due to the wrong parameters and
template patterns.

Print subcommand help 

Update with linkerd metric fix, fix scale to zero bug

Add support for printing out the help for a specific
subcommand when a commands matching the form rio SUBCOMMAND --help
are entered.

Fix linkerd header to include activator as header override so that
when service is scaled to zero it sends traffic to activator service

Only deploy socat with hostNetwork to proxy registry

For local registry we previously use hostport to expose registry service
to localhost:5442. Since hostports are wonky and won't work in every k8s
distro, switching to socat container with hostNetwork: true would be the
best solution

Fix publicdomain failing to create certificates

Fix traffic split issue

Fix hostport install stucking at gateway