fix(deps): update dependency chai to ^4.2.0

Author: renovate-bot

package-lock.json

@@ -41,7 +41,7 @@
     ]
   },
   "dependencies": {
-    "chai": "^4.0.1",
+    "chai": "^4.2.0",
     "chai-as-promised": "^7.0.0",
     "chalk": "^2.2.0",
     "commander": "^2.9.0",
@@ -67,7 +67,7 @@
     "@sourcegraph/prettierrc": "^3.0.2",
     "@sourcegraph/tsconfig": "^3.0.0",
     "@sourcegraph/tslint-config": "^12.3.1",
-    "@types/chai": "4.1.7",
+    "@types/chai": "4.2.11",
     "@types/chai-as-promised": "7.1.0",
     "@types/glob": "7.1.1",
     "@types/lodash": "4.14.149",