Bump ajv from 6.12.3 to 6.12.4

Bumps [ajv](https://github.com/ajv-validator/ajv) from 6.12.3 to 6.12.4.
- [Release notes](https://github.com/ajv-validator/ajv/releases)
- [Commits](https://github.com/ajv-validator/ajv/compare/v6.12.3...v6.12.4)

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

package-lock.json

@@ -76,9 +76,9 @@
       }
     },
     "ajv": {
-      "version": "6.12.3",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.3.tgz",
-      "integrity": "sha512-4K0cK3L1hsqk9xIb2z9vs/XU+PGJZ9PNpJRDS9YLzmNdX6jmVPfamLvTJr0aDAusnHyCHO6MjzlkAsgtqp9teA==",
+      "version": "6.12.4",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.4.tgz",
+      "integrity": "sha512-eienB2c9qVQs2KWexhkrdMLVDoIQCz5KSeLxwg9Lzk4DOfBtIK9PQwwufcsn1jjGuf9WZmqPMbGxOzfcuphJCQ==",
       "requires": {
         "fast-deep-equal": "^3.1.1",
         "fast-json-stable-stringify": "^2.0.0",
@@ -1287,9 +1287,9 @@
       "integrity": "sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q=="
     },
     "fast-json-stable-stringify": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/fast-json-stable-stringify/-/fast-json-stable-stringify-2.0.0.tgz",
-      "integrity": "sha1-1RQsDK7msRifh9OnYREGT4bIu/I="
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/fast-json-stable-stringify/-/fast-json-stable-stringify-2.1.0.tgz",
+      "integrity": "sha512-lhd/wF+Lk98HZoTCtlVraHtfh5XYijIjalXck7saUtuanSDyLMxnHhSXEDJqHxD7msR8D0uCmqlkwjCV8xvwHw=="
     },
     "fast-levenshtein": {
       "version": "2.0.6",

package.json

@@ -18,7 +18,7 @@
     "url": "https://github.com/Dragory/modmailbot"
   },
   "dependencies": {
-    "ajv": "^6.12.3",
+    "ajv": "^6.12.4",
     "eris": "^0.13.3",
     "humanize-duration": "^3.12.1",
     "ini": "^1.3.5",