DP-9854: Update babelify dependency

[rbayliss]

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Description

This is a followup to the security update(#75) to update a dependency that was a little too complicated to handle in the scope of the update ticket. This PR updates babelify, which required adding the babel-core and babel-preset-env packages. Babel will now build javascript based on our .browserlistrc file (same as our SCSS).

Related Issue / Ticket

• JIRA issue

Steps to Test

1. Using multiple browsers, find javascript heavy pages in Mayflower and try them out. Some examples:
   • Location listing pages
   • Event listing pages
   • Etc..
2. Make sure all javascript functionality matches what's currently on https://mayflower.digital.mass.gov/.

Screenshots

Use something like licecap to capture gifs to demonstrate behaviors.

Additional Notes:

Anything else to add?

Impacted Areas in Application

@todo

Today I learned...

[mrossi113]

👍 LGTM! Tested the location listing and event listing pages in multiple browsers: Firefox ESR, Firefox 61, Chrome 67, and IE 11.

[ygannett]

LGTM. Ready to merge.