fix(deps): update dependency mathjs to v7 (#400)

Author: renovate-bot

automl/package.json

@@ -18,7 +18,7 @@
   "dependencies": {
     "@google-cloud/automl": "^2.0.0",
     "csv": "^5.1.3",
-    "mathjs": "^6.0.0",
+    "mathjs": "^7.0.0",
     "yargs": "^15.0.0"
   },
   "devDependencies": {