Create simple version of ratelimit package

Allows for more testing.

pkg/util/workqueue/BUILD

@@ -25,8 +25,8 @@ go_library(
     tags = ["automanaged"],
     deps = [
         "//pkg/util/clock:go_default_library",
+        "//pkg/util/ratelimit:go_default_library",
         "//pkg/util/runtime:go_default_library",
-        "//vendor:github.com/juju/ratelimit",
     ],
 )
 

pkg/util/workqueue/default_rate_limiters.go

@@ -21,7 +21,7 @@ import (
 	"sync"
 	"time"
 
-	"github.com/juju/ratelimit"
+	"k8s.io/kubernetes/pkg/util/ratelimit"
 )
 
 type RateLimiter interface {
@@ -35,7 +35,7 @@ type RateLimiter interface {
 }
 
 // DefaultControllerRateLimiter is a no-arg constructor for a default rate limiter for a workqueue.  It has
-// both overall and per-item rate limitting.  The overall is a token bucket and the per-item is exponential
+// both overall and per-item rate limiting.  The overall is a token bucket and the per-item is exponential
 func DefaultControllerRateLimiter() RateLimiter {
 	return NewMaxOfRateLimiter(
 		NewItemExponentialFailureRateLimiter(5*time.Millisecond, 1000*time.Second),