Bump core-js from 3.6.1 to 3.6.3 in /client

[dependabot-preview]

Bumps core-js from 3.6.1 to 3.6.3.

Changelog

Sourced from core-js's changelog.

3.6.3 - 2020.01.11

• Fixed replacement of substitutes of undefined capture groups in .replace in Safari 13.0-, #471, #745, thanks @mattclough1
• Improved compat data for old engines

3.6.2 - 2020.01.07

• Fixed early implementations of Array#{ every, forEach, includes, indexOf, lastIndexOf, reduce, reduceRight, slice, some, splice } for the usage of ToLength
• Added RegExp#exec dependency to methods which depends on the correctness of logic of this method (3.6.0-3.6.1 issue), #741
• Refactored some internals

Commits

• 1e63de1 3.6.3
• 6f80aac some missed actions for #745
• 254a227 fixes #471 (#745)
• b9ffdfe some stylistic changes in the documentation
• 113ecbb add a warning about specifying minor core-js version
• 241537f fix esnext.iterator.constructor compat test (some old FF versions with non-...
• c7c5015 update the changelog
• b5490f6 update compat data
• 5aedc36 update es.function.name module compat data
• 9ba1282 update compat data
• Additional commits viewable in compare view

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot squash and merge will squash and merge this PR after your CI passes on it
• @dependabot cancel merge will cancel a previously requested merge and block automerging
• @dependabot reopen will reopen this PR if it is closed
• @dependabot close will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
• @dependabot ignore this major version will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this minor version will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
• @dependabot use these labels will set the current labels as the default for future PRs for this repo and language
• @dependabot use these reviewers will set the current reviewers as the default for future PRs for this repo and language
• @dependabot use these assignees will set the current assignees as the default for future PRs for this repo and language
• @dependabot use this milestone will set the current milestone as the default for future PRs for this repo and language
• @dependabot badge me will comment on this PR with code to add a "Dependabot enabled" badge to your readme

Additionally, you can set the following in your Dependabot dashboard:

• Update frequency (including time of day and day of week)
• Pull request limits (per update run and/or open at any time)
• Out-of-range updates (receive only lockfile updates, if desired)
• Security updates (receive only security updates, if desired)