Bump ajv from 5.2.5 to 6.12.3 in /samples/react-directory

Bumps [ajv](https://github.com/ajv-validator/ajv) from 5.2.5 to 6.12.3.
- [Release notes](https://github.com/ajv-validator/ajv/releases)
- [Commits](https://github.com/ajv-validator/ajv/compare/v5.2.5...v6.12.3)

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

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

samples/react-directory/package-lock.json

@@ -9951,27 +9951,21 @@
       }
     },
     "ajv": {
-      "version": "5.2.5",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-5.2.5.tgz",
-      "integrity": "sha1-tjcjTT4mdetfefxlIkKoU6SMtJ8=",
+      "version": "6.12.3",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.3.tgz",
+      "integrity": "sha512-4K0cK3L1hsqk9xIb2z9vs/XU+PGJZ9PNpJRDS9YLzmNdX6jmVPfamLvTJr0aDAusnHyCHO6MjzlkAsgtqp9teA==",
       "dev": true,
       "requires": {
-        "co": "^4.6.0",
-        "fast-deep-equal": "^1.0.0",
-        "json-schema-traverse": "^0.3.0",
-        "json-stable-stringify": "^1.0.1"
+        "fast-deep-equal": "^3.1.1",
+        "fast-json-stable-stringify": "^2.0.0",
+        "json-schema-traverse": "^0.4.1",
+        "uri-js": "^4.2.2"
       },
       "dependencies": {
         "fast-deep-equal": {
-          "version": "1.1.0",
-          "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-1.1.0.tgz",
-          "integrity": "sha1-wFNHeBfIa1HaqFPIHgWbcz0CNhQ=",
-          "dev": true
-        },
-        "json-schema-traverse": {
-          "version": "0.3.1",
-          "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-0.3.1.tgz",
-          "integrity": "sha1-NJptRMU6Ud6JtAgFxdXlm0F9M0A=",
+          "version": "3.1.3",
+          "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz",
+          "integrity": "sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q==",
           "dev": true
         }
       }

samples/react-directory/package.json

@@ -49,7 +49,7 @@
     "@types/react-dom": "16.8.3",
     "@types/webpack-env": "1.13.1",
     "@voitanos/jest-preset-spfx-react16": "^1.1.0",
-    "ajv": "~5.2.2",
+    "ajv": "~6.12.3",
     "gulp": "~3.9.1",
     "gulp-sequence": "1.0.0",
     "jest": "^23.6.0",