chore: fix eslint config

Author: andreypopp

package.json

@@ -15,6 +15,10 @@
     "extends": "prometheusresearch",
     "env": {
       "mocha": true
+    },
+    "globals": {
+      "expr": true,
+      "stmt": true
     }
   },
   "scripts": {
@@ -55,4 +59,4 @@
     "babel-generator": "^6.7.5",
     "eslint-plugin-react": "^4.3.0"
   }
-}
+}