Update transformation: removeDeprecatedPlugins

[bitpshr]

Do you want to request a feature or report a bug?
Feature

What is the current behavior?
The current transformation supports migrating a webpack configuration from v1 to v2.

What is the expected behavior?
The transformation should support migrating a webpack configuration from v3 to v4.

If this is a feature request, what is motivation or use case for changing the behavior?
After some discussion the decision was made to update our migration transformations to actively support migrating only from the previous version to the current version, which currently means v3 - v4. Migrating older versions such as v1 or v2 will no longer be supported.

This feature request is to update the removeDeprecatedPlugins transformation accordingly.

[matheus1lva]

Plugins to be removed?:

• webpack.optimize.CommonsChunkPlugin (Feature: Migrate should move CommonsChunkPlugin to SplitChunksPlugin #393)
• webpack.optimize.UglifyJsPlugin (which is done by Update UglifyJSPlugin transformation #401 )

[ematipico]

• CommonsChunkPlugin is not deprecated but it's been changed in favor of splitChunks, which is covered already in another PR
• not deprecated but changed

I don't think we have plugins have been totally removed.

[matheus1lva]

Yep, if forgot we have a PR open for split chunks too. I just updated my comment. We can close this i guess