defaults: set default concurrency parameter to 10

Author: aschmahmann

dht_options.go

@@ -117,7 +117,7 @@ var defaults = func(o *config) error {
 	o.maxRecordAge = time.Hour * 36
 
 	o.bucketSize = defaultBucketSize
-	o.concurrency = 3
+	o.concurrency = 10
 	o.resiliency = 3
 
 	o.v1CompatibleMode = true
@@ -281,7 +281,7 @@ func BucketSize(bucketSize int) Option {
 
 // Concurrency configures the number of concurrent requests (alpha in the Kademlia paper) for a given query path.
 //
-// The default value is 3.
+// The default value is 10.
 func Concurrency(alpha int) Option {
 	return func(c *config) error {
 		c.concurrency = alpha