Update eslint-plugin-import requirement from 2.17.3 to 2.18.0

Updates the requirements on [eslint-plugin-import](https://github.com/benmosher/eslint-plugin-import) to permit the latest version.
- [Release notes](https://github.com/benmosher/eslint-plugin-import/releases)
- [Changelog](https://github.com/benmosher/eslint-plugin-import/blob/master/CHANGELOG.md)
- [Commits](import-js/eslint-plugin-import@v2.17.3...v2.18.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Author: dependabot-preview[bot]

package.json

@@ -23,7 +23,7 @@
     "chai": "4.2.0",
     "eslint": "4.19.0",
     "eslint-config-airbnb-base": "12.1.0",
-    "eslint-plugin-import": "2.17.3",
+    "eslint-plugin-import": "2.18.0",
     "mocha": "6.1.4"
   },
   "keywords": [