Feature request: Ability to skip installing a plugin if already installed

[andrucz]

I've created a script for Travis with the following commands:

before_install:
  - sudo apt-get install -y libsecret-1-dev

  - npm install twilio-cli -g
  - twilio plugins:install @twilio-labs/plugin-flex

twilio plugins:install always takes around a minute to finish and installs the same version in the majority of builds, so I'd like to add the installation to the build cache and skip installing it when there are no updates.

[isha689]

@andrucz Thank you for raising this request. It has been added to our internal backlog to be prioritised. Pull requests and +1s on the feature request will help it move up the backlog.