Bump core-js from 3.1.3 to 3.1.4

[dependabot-preview]

Bumps core-js from 3.1.3 to 3.1.4.

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.

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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