Don't neet to wait 15 seconds before checking if lock has been removed.

cache/global_lock.go

diff --git a/cache/global_lock.go b/cache/global_lock.go
index ad6eec5..52cf841 100644
--- a/cache/global_lock.go
+++ b/cache/global_lock.go
@@ -106,6 +106,6 @@
 
 		// Check on the lock file every 15 seconds.
 		// TODO(mattfarina): should this be a different length?
-		time.Sleep(15 * time.Second)
+		time.Sleep(time.Second)
 	}
 }