[eslint config] [base] [patch] Ignore property modifications of staticContext params

React Router passes a `staticContext` property to children to allow
signalling status codes and redirected URLs, by allowing children to
assign property values to it during render

packages/eslint-config-airbnb-base/rules/best-practices.js

@@ -186,6 +186,7 @@ module.exports = {
         'res', // for Express responses
         'response', // for Express responses
         '$scope', // for Angular 1 scopes
+        'staticContext', // for ReactRouter context
       ]
     }],