Update core-js requirement from ^2.5.1 to ^3.1.4

[dependabot-preview]

Updates the requirements on core-js to permit the latest version.

Changelog

Sourced from core-js's changelog.

3.1.4 - 2019.06.15

• Refactoring. Many minor internal improvements and fixes like:
  • Improved Symbol.keyFor complexity to O(1)
  • Fixed the order of arguments validation in String.prototype.{ endsWith, includes, startsWith }
  • Internal implementation of RegExp#flags helper now respect dotAll flag (mainly ralated to the pure version)
  • Performace optimizations related old V8
  • Etc.

3.1.3 - 2019.05.27

• Fixed core-js/features/reflect/delete-metadata entry point
• Some fixes and improvements of the postinstall script like support npm color config (#556) or adding support of ADBLOCK env variable
• Refactoring and some minor fixes

2.6.9 [LEGACY] - 2019.05.27

• Some fixes and improvements of the postinstall script like support npm color config (#556) or adding support of ADBLOCK env variable

3.1.2 - 2019.05.22

• Added a workaround of a strange npx bug on postinstall, #551

2.6.8 [LEGACY] - 2019.05.22

• Added a workaround of a strange npx bug on postinstall, #551

3.1.1 - 2019.05.21

• Added one more workaround of alternative not completely correct Symbol polyfills, #550, #554
• Reverted esnext.string.match-all in some entry points for fix autogeneration of core-js-compat/entries and backward @babel/preset-env compatibility

2.6.7 [LEGACY] - 2019.05.21

• Added one more workaround of alternative not completely correct Symbol polyfills, #550, #554

3.1.0 - 2019.05.20

• String#matchAll moved to stable ES, exposed Symbol.matchAll, #516
• Promise.allSettled moved to stage 3, #515
• String#replaceAll moved to stage 2, behavior updated by the spec draft, #524
• Promise.any moved to stage 1, #517
• Removed es.regexp.flags dependency from es.regexp.to-string, #536, #537
• Fixed IE8- non-enumerable properties support in Object.{ assign, entries, values }, #541
• Fixed support of primitives in Object.getOwnPropertySymbols in Chrome 38 / 39, #539
• window.postMessage-based task implementation uses location origin over '*', #542
• Lookup PromiseConstructor.resolve only once in Promise combinators, tc39/ecma262#1506
• Temporarily removed core-js dependency from core-js-compat since it's required for missed at this moment feature
• Show a message on postinstall
• Added compat data for Chrome 76, FF 67, Node 12

2.6.6 [LEGACY] - 2019.05.20

• Fixed IE8- non-enumerable properties support in Object.{ assign, entries, values }, #541
• Fixed support of primitives in Object.getOwnPropertySymbols in Chrome 38 / 39, #539
• Show a message on postinstall

3.0.1 - 2019.04.06

• Fixed some cases of work with malformed URI sequences in URLSearchParams, #525

... (truncated)

Commits

• b8e3502 3.1.4
• 1b57b6c update dependencies
• 8f52a83 add Tidelift
• bc7e3be improve some cases of work with iterables
• 8714aec update dependencies
• eef118e some stylistic changes
• 93fa08f improve Symbol.keyFor to O(1) complexity
• ac4deb1 extend import/no-cycle rule to commonjs
• e6dcb0e some stylistic changes
• d7afec0 fix the order of arguments validation in `String.prototype.{ endsWith, includ...
• Additional commits viewable in compare view

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[dependabot-preview]

Superseded by #32.