Remove PEP

[srallen]

Please request review from @zooniverse/frontend team. If PR is related to design, please request review from @beckyrother in addition.

Package: lib-classifier

PEP is entering a kind of EOL (see #2035) and I'm suspecting it may be the cause of a few Sentry reported bugs and potentially a silent bug with an occasional duplicate mark being created with the transcription line tool. I haven't been able to replicate the issue of duplicate marks, but we're gonna try this out since we have to do this anyway.

There shouldn't be any regressions, other than support for Safari 12 is dropped, but to double check anyway: https://localhost:8080/?project=1764&workflow=3392

Review Checklist

General

• Are the tests passing locally and on Travis?
• Is the documentation up to date?

Components

• Has a storybook story been created or updated?
• Is the component accessible?
  • Can it be used with a screen reader? BBC guide to testing with VoiceOver
  • Can it be used from the keyboard? WebAIM guide to keyboard testing
  • Is it passing accessibility checks in the storybook?

Apps

• Does it work in all major browsers: Firefox, Chrome, Edge, Safari?
• Does it work on mobile?
• Can you yarn panic && yarn bootstrap or docker-compose up --build and app works as expected?

Publishing

• Is the changelog updated?
• Are the dependencies updated for apps and libraries that are using the newly published library?

Post-merging

• Did the app deploy to https://frontend.preview.zooniverse.org/projects/:project-name/:owner or https://frontend.preview.zooniverse.org/about?
• Is the new feature working or bug now fixed?
  • Is there a Talk or blog post written to announce the new feature(s)?
• Is the design working across browsers (Firefox, Chrome, Edge, Safari) and mobile?
  • Is this approved by our designer?
• Is this ready for production deployment?

[eatyourgreens]

Changes look good. The touch-action attribute can be removed from the HTML too.