Adds env command: push, pull, ls

[jritsema]

push scenarios

• works better with terraform so you don't have to maintain a full/duplicate hc.yml to run up
• stage envvars without deploying

  harbor-compose envvars push
  harbor-compose envvars push [--hidden secrets.env]
  harbor-compose envvars push [-s app -e dev]

pull scenarios

• already have compose files and want to update hidden.env from another colleague

  harbor-compose envvars pull

• want to test a different environment like QA, and don't have any files (or only a docker-compose.yml)

  harbor-compose envvars pull -s my-app -e qa --env-file qa.env

list

harbor-compose envvars ls

SHIPMENT: my-app
ENVIRONMENT: dev

NAME            VALUE                                        TYPE
LOGS_ENDPOINT   https://listener.logz.io:8071?token=xxxxxx   hidden
SHIP_LOGS       true                                         hidden

CONTAINER: my-container

NAME          VALUE     TYPE
FOO           bar       basic
HEALTHCHECK   /health   basic
PORT          5000      basic

[jritsema]

Thinking about renaming this new envvars command to env. Thoughts?