feat(exclude): regroup all exclusion logic

Also add a filter function to exclude custom request

lib/exclude.js

@@ -0,0 +1,34 @@
+
+export default function exclude (req, service, exclusions = {}) {
+  if (service) {
+    if (service.use && service.use.cache === false) {
+      return true
+    }
+  }
+
+  if ((typeof exclusions.filter === 'function') && !exclusions.filter(req)) {
+    return true
+  }
+
+  // do not cache request with query
+  if (exclusions.query && req.url.match(/\?.*$/)) {
+    return true
+  }
+
+  let found = false
+  const paths = exclusions.paths || []
+
+  paths.forEach(regexp => {
+    if (req.url.match(regexp)) {
+      found = true
+      return found
+    }
+  })
+
+  if (found) {
+    return true
+  }
+
+  // All rules explained. fo not rewrite regexp.
+  return false
+}