[eslint config] [base] [minor] add **/*.spec.js as a test files pattern

(see airbnb#1131)

Author: stevemao

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

@@ -76,6 +76,7 @@ module.exports = {
         'test.js', // repos with a single test file
         'test-*.js', // repos with multiple top-level test files
         '**/*.test.js', // tests where the extension denotes that it is a test
+        '**/*.spec.js', // tests where the extension denotes that it is a test
         '**/webpack.config.js', // webpack config
         '**/webpack.config.*.js', // webpack config
         '**/rollup.config.js', // rollup config