test: Add Jest root to package.json

Author: nodkz

package.json

@@ -56,6 +56,11 @@
       "path": "./node_modules/cz-conventional-changelog"
     }
   },
+  "jest": {
+    "roots": [
+      "<rootDir>/src"
+    ]
+  },
   "scripts": {
     "build": "npm run build-cjs && npm run build-flow",
     "build-cjs": "rimraf lib && babel src --ignore __tests__,__mocks__ -d lib",