Updated the files.

my-app/node_modules/karma/lib/utils/file-utils.js

@@ -0,0 +1,25 @@
+'use strict'
+
+const fs = require('graceful-fs')
+
+const FileUtils = {
+  readFile (path) {
+    return fs.readFileSync(path).toString()
+  },
+
+  saveFile (path, content) {
+    fs.writeFileSync(path, content)
+  },
+
+  copyFile (src, dest) {
+    FileUtils.saveFile(dest, FileUtils.readFile(src))
+  },
+
+  removeFileIfExists (src) {
+    if (fs.existsSync(src)) {
+      fs.unlinkSync(src)
+    }
+  }
+}
+
+module.exports = FileUtils