v1.20.0

• Add env-get command to retrieve the value of a specific environment variable #643
• Error message are outputted on stderr #639
• Automatically prefix the integration URL with https if none is provided #642
• backups-download downloads the most recent backup if none is specified #636
• Add deployment-cache-delete as an alias to deployment-delete-cache #635
• one-off-stop command to stop a running one-off container #633
• ps command returns the list of application's containers #632
• ps command is renamed scale #631
• Show the addon status on scalingo addons #604
• Add informative error in case of container type error when scaling an application
  602
• Update various dependencies:
  • github.com/fatih/color
  • github.com/briandowns/spinner
  • github.com/gosuri/uilive
  • github.com/stretchr/testify
  • github.com/urfave/cli
  • gopkg.in/AlecAivazis/survey.v1
  • github.com/cheggaaa/pb
  • gopkg.in/src-d/go-git.v4
  • github.com/Scalingo/go-scalingo/v4
  • github.com/ScaleFT/sshkeys
  • github.com/heroku/hk
  • github.com/howeyc/gopass
  • github.com/olekukonko/tablewriter
  • golang.org/x/crypto
  • golang.org/x/net
• Update Scalingo internal dependencies to the Go Modules version #613