Merge branch 'allow-to-configure-cache-path' into 'master'

Allow to configure cache path for webpack

See merge request gitlab-org/gitlab-ce!22497

config/webpack.config.js

@@ -8,7 +8,7 @@ const MonacoWebpackPlugin = require('monaco-editor-webpack-plugin');
 const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
 
 const ROOT_PATH = path.resolve(__dirname, '..');
-const CACHE_PATH = path.join(ROOT_PATH, 'tmp/cache');
+const CACHE_PATH = process.env.WEBPACK_CACHE_PATH || path.join(ROOT_PATH, 'tmp/cache');
 const IS_PRODUCTION = process.env.NODE_ENV === 'production';
 const IS_DEV_SERVER = process.argv.join(' ').indexOf('webpack-dev-server') !== -1;
 const DEV_SERVER_HOST = process.env.DEV_SERVER_HOST || 'localhost';