Update eslint requirement from ^1.10.3 to ^2.13.1 (#9)

Updates the requirements on [eslint](https://github.com/eslint/eslint) to permit the latest version.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/eslint/eslint/commits/v2.13.1)

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

package.json

@@ -26,7 +26,7 @@
     "hexo": "^3.1.1",
     "mocha": "^5.2.0",
     "istanbul": "^0.4.2",
-    "eslint": "^1.10.3",
+    "eslint": "^2.13.1",
     "jscs": "^2.9.0",
     "eslint-config-hexo": "^1.0.2",
     "jscs-preset-hexo": "^1.0.1"