Bump axios from 0.15.3 to 0.21.1

Bumps [axios](https://github.com/axios/axios) from 0.15.3 to 0.21.1.
- [Release notes](https://github.com/axios/axios/releases)
- [Changelog](https://github.com/axios/axios/blob/master/CHANGELOG.md)
- [Commits](axios/axios@v0.15.3...v0.21.1)

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

Author: dependabot[bot]

package.json

@@ -7,7 +7,7 @@
     "production": "node node_modules/cross-env/bin/cross-env.js NODE_ENV=production node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js"
   },
   "devDependencies": {
-    "axios": "^0.15.2",
+    "axios": "^0.21.1",
     "bootstrap-sass": "^3.3.7",
     "jquery": "^3.1.0",
     "laravel-mix": "^0.6.0",