Bump json-schema and jsprim in /generator-exercise

Bumps [json-schema](https://github.com/kriszyp/json-schema) and [jsprim](https://github.com/joyent/node-jsprim). These dependencies needed to be updated together.

Updates `json-schema` from 0.2.3 to 0.4.0
- [Release notes](https://github.com/kriszyp/json-schema/releases)
- [Commits](https://github.com/kriszyp/json-schema/compare/v0.2.3...v0.4.0)

Updates `jsprim` from 1.4.1 to 1.4.2
- [Release notes](https://github.com/joyent/node-jsprim/releases)
- [Changelog](https://github.com/TritonDataCenter/node-jsprim/blob/v1.4.2/CHANGES.md)
- [Commits](https://github.com/joyent/node-jsprim/compare/v1.4.1...v1.4.2)

---
updated-dependencies:
- dependency-name: json-schema
  dependency-type: indirect
- dependency-name: jsprim
  dependency-type: indirect
...

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

generator-exercise/package-lock.json

@@ -2932,12 +2932,6 @@
       "integrity": "sha1-RsP+yMGJKxKwgz25vHYiF226s0s=",
       "dev": true
     },
-    "json-schema": {
-      "version": "0.2.3",
-      "resolved": "https://registry.npmjs.org/json-schema/-/json-schema-0.2.3.tgz",
-      "integrity": "sha1-tIDIkuWaLwWVTOcnvT8qTogvnhM=",
-      "dev": true
-    },
     "json-stable-stringify": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/json-stable-stringify/-/json-stable-stringify-1.0.1.tgz",
@@ -2972,21 +2966,27 @@
       "dev": true
     },
     "jsprim": {
-      "version": "1.4.1",
-      "resolved": "https://registry.npmjs.org/jsprim/-/jsprim-1.4.1.tgz",
-      "integrity": "sha1-MT5mvB5cwG5Di8G3SZwuXFastqI=",
+      "version": "1.4.2",
+      "resolved": "https://registry.npmjs.org/jsprim/-/jsprim-1.4.2.tgz",
+      "integrity": "sha512-P2bSOMAc/ciLz6DzgjVlGJP9+BrJWu5UDGK70C2iweC5QBIeFf0ZXRvGjEj2uYgrY2MkAAhsSWHDWlFtEroZWw==",
       "dev": true,
       "requires": {
         "assert-plus": "1.0.0",
         "extsprintf": "1.3.0",
-        "json-schema": "0.2.3",
+        "json-schema": "0.4.0",
         "verror": "1.10.0"
       },
       "dependencies": {
         "assert-plus": {
           "version": "1.0.0",
           "resolved": "https://registry.npmjs.org/assert-plus/-/assert-plus-1.0.0.tgz",
-          "integrity": "sha1-8S4PPF13sLHN2RRpQuTpbB5N1SU=",
+          "integrity": "sha512-NfJ4UzBCcQGLDlQq7nHxH+tv3kyZ0hHQqF5BO6J7tNJeP5do1llPr8dZ8zHonfhAu0PHAdMkSo+8o0wxg9lZWw==",
+          "dev": true
+        },
+        "json-schema": {
+          "version": "0.4.0",
+          "resolved": "https://registry.npmjs.org/json-schema/-/json-schema-0.4.0.tgz",
+          "integrity": "sha512-es94M3nTIfsEPisRafak+HDLfHXnKBhV3vU5eqPcS3flIWqcxJWgXHXiey3YrpaNsanY5ei1VoYEbOzijuq9BA==",
           "dev": true
         }
       }