Bump serverless-webpack from 3.1.2 to 5.13.0

Bumps [serverless-webpack](https://github.com/serverless-heaven/serverless-webpack) from 3.1.2 to 5.13.0.
- [Release notes](https://github.com/serverless-heaven/serverless-webpack/releases)
- [Commits](serverless-heaven/serverless-webpack@v3.1.2...v5.13.0)

---
updated-dependencies:
- dependency-name: serverless-webpack
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

package.json

@@ -16,7 +16,7 @@
     "babel-plugin-transform-runtime": "^6.23.0",
     "babel-preset-es2015": "^6.24.1",
     "babel-preset-stage-3": "^6.24.1",
-    "serverless-webpack": "^3.1.0",
+    "serverless-webpack": "^5.13.0",
     "webpack": "^3.6.0",
     "webpack-node-externals": "^1.6.0"
   },