Bump lint-staged from 7.0.3 to 7.0.4 (gae-init#842)

Bumps [lint-staged](https://github.com/okonet/lint-staged) from 7.0.3 to 7.0.4.
- [Release notes](https://github.com/okonet/lint-staged/releases)
- [Commits](lint-staged/lint-staged@v7.0.3...v7.0.4)

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

package.json

@@ -32,7 +32,7 @@
     "gulp-zip": "4.1.0",
     "husky": "0.14.3",
     "less": "2.7.3",
-    "lint-staged": "7.0.3",
+    "lint-staged": "7.0.4",
     "main-bower-files": "2.13.1",
     "prettier": "1.12.0",
     "require-dir": "1.0.0",