Fix dockerfile

The Dockerfile wasn't including all the node modules

Base image update

This update is primarily to fix image vulnerabilities by updating node.js, node.js pacakges, and the underlying Alpine Linux image.

• Update the base image to mhart/alpine-node:12/13.
• Add package updates to Dockerfile build.
• Upgrade node.js packages in case of vulnerabilities.
• Update CircleCI build with Node 12.13 and Kubernetes 1.14.8.
• Remove old nvm so that Circle updates it.

Istio DestinationPolicy and current updates

Drafting the 0.2.0 release to capture current state of Skipper before 0.2.1, which will update many dependencies.

Add Istio DestinationPolicy support

Merge pull request #21 from emaildanwilson/addIstioDestinationPolicy

add Istio destinationpolicies

Start version tracking

• Adds support for Istio EgressRule & RouteRule object types.