Fix lint issue.

Author: davidlehn

lib/test.js

@@ -138,7 +138,7 @@ async function runMocha(state) {
       let pretty = null;
       try {
         pretty = JSON.stringify(obj, null, 2);
-      } catch(e) {
+      } catch {
         // we need to remove circular references from the json
         // in order to pretty print with JSON.stringify
         pretty = JSON.stringify(cycle.decycle(obj), null, 2);