Forbid console.log and console.info

Console calls, IMO, should be for debugging only. They're useful
for users facing bugs to share information about any unexpected events.
Instead of using `console.log` as a catch-all, I'd like to think more
carefully about the purpose of each message, and either omit or
log it as an error, warning, or debug message.

Author: mfisher87

.eslintrc.js

@@ -51,6 +51,7 @@ module.exports = {
       }
     ],
     "prefer-arrow-callback": "error",
+    "no-console": ["error", {"allow": ["error", "warn", "debug"]}],
     "no-duplicate-imports": "error",
   },
 };