Add --configuration parameter

[MarioC3]

The Ionic CLI currently supports the --configuration parameter on ionic cordova prepare.
https://ionicframework.com/docs/cli/commands/cordova-prepare#advanced-options

It looks like there was already a PR to include this, but it was never merged:
#51

Is there any plans to merge this?

[fortu42]

+1 for this

[aleixfargas]

+1 for this too

[staskuban]

+1

[kabaehr]

+1