Upgrade dependent packages to the latest version

[yhatt]

Notable changes

• Linters (ESLint and stylelint) have major updates.
  • Both of them have dropped the outdated Node.js 10 support, so now CI process for Node.js 10 is only running test.
  • Update to use stylelint-config-standard-sass shared config instead of stylelint-config-standard config and stylelint-sass plugin.
• Codecov has announced a deprecation plan for the language-specific uploader. We may receive the effect of brownout if continued to use codecov Node package. Thus, we have migrated to use a new standalone uploader through CircleCI orb.