Update all dependencies

Godeps/_workspace/src/github.com/juju/ratelimit/README.md

@@ -20,7 +20,7 @@ token in the bucket represents one byte.
 ```go
 func Writer(w io.Writer, bucket *Bucket) io.Writer
 ```
-Writer returns a reader that is rate limited by the given token bucket. Each
+Writer returns a writer that is rate limited by the given token bucket. Each
 token in the bucket represents one byte.
 
 #### type Bucket

Godeps/_workspace/src/github.com/juju/ratelimit/ratelimit.go

@@ -2,15 +2,16 @@
 // Licensed under the LGPLv3 with static-linking exception.
 // See LICENCE file for details.
 
-// The ratelimit package provides an efficient token bucket implementation.
+// The ratelimit package provides an efficient token bucket implementation
+// that can be used to limit the rate of arbitrary things.
 // See http://en.wikipedia.org/wiki/Token_bucket.
 package ratelimit
 
 import (
-	"math"
 	"strconv"
 	"sync"
 	"time"
+	"math"
 )
 
 // Bucket represents a token bucket that fills at a predetermined rate.