[eslint config] [base] [patch] loosen no-extraneous-dependencies for test files.

Relates to airbnb#959, airbnb#1089.

Author: ljharb

packages/eslint-config-airbnb-base/rules/imports.js

@@ -66,8 +66,9 @@ module.exports = {
 
     // Forbid the use of extraneous packages
     // https://github.com/benmosher/eslint-plugin-import/blob/master/docs/rules/no-extraneous-dependencies.md
+    // paths are treated both as absolute paths, and relative to process.cwd()
     'import/no-extraneous-dependencies': ['error', {
-      devDependencies: false,
+      devDependencies: ['spec/**', 'test/**', 'tests/**', '**/__tests__/**'],
       optionalDependencies: false,
     }],