[now dev] Use pcre-to-regexp to match routes (#2027)

* [now dev] Use `pcre-to-regexp` to match `routes`

The now.json `routes` support PCRE syntax like named captures,
so use the `pcre-to-regexp` module to match the routes.

Fixes #2023.

* Pass the resolved router `dest` and query params to the Lambda

test/dev-router.unit.js

@@ -36,7 +36,7 @@ test('[dev-router] captured groups', t => {
 
 test('[dev-router] named groups', t => {
   const routesConfig = [
-    { src: '/user/(?<id>.+)', dest: '/user.js?id=$<id>' }
+    { src: '/user/(?<id>.+)', dest: '/user.js?id=$id' }
   ];
   const result = devRouter('/user/123', routesConfig);