feat(linter): fixing linting

Author: Piotr Wyrobek

src/index.js

@@ -57,10 +57,10 @@ module.exports = (userOptions = {}) => {
     // will replace ids from the route with `#val` placeholder this serves to
     // measure the same routes, e.g., /image/id1, and /image/id2, will be
     // treated as the same route
-    const customNormalizedPath = typeof option.customUrlNormalizer === 'function' ?
-      option.customPathNormalizer(originalUrl, req, res) : null;
+    const customNormalizedPath = typeof options.customUrlNormalizer === 'function'
+      ? options.customPathNormalizer(originalUrl, req, res) : null;
 
-    const route = normalizePath(customNormalizedPath|| originalUrl, options.extraMasks);
+    const route = normalizePath(customNormalizedPath || originalUrl, options.extraMasks);
 
     if (route !== metricsPath) {
       const status = normalizeStatus