Bump ajv from 6.5.3 to 6.12.3

Bumps [ajv](https://github.com/ajv-validator/ajv) from 6.5.3 to 6.12.3.
- [Release notes](https://github.com/ajv-validator/ajv/releases)
- [Commits](ajv-validator/ajv@v6.5.3...v6.12.3)

---
updated-dependencies:
- dependency-name: ajv
  dependency-type: direct:development
...

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

Author: dependabot[bot]

package-lock.json

@@ -23,7 +23,7 @@
     "@babel/preset-env": "^7.4.3",
     "@babel/register": "^7.0.0",
     "@babel/runtime": "^7.0.0",
-    "ajv": "^6.5.3",
+    "ajv": "^6.12.3",
     "babel-loader": "^8.0.0",
     "babel-plugin-transform-import-bangtext-node": "^0.1.4",
     "bower": "^1.8.0",