add TTL to consul lock using store.LockOptions and add tests for the Lock ttl behavior

Signed-off-by: Alexandre Beslic <abronan@docker.com>

libnetwork/internal/kvstore/kvstore.go

@@ -113,13 +113,14 @@ type WriteOptions struct {
 
 // LockOptions contains optional request parameters
 type LockOptions struct {
-	Value []byte        // Optional, value to associate with the lock
-	TTL   time.Duration // Optional, expiration ttl associated with the lock
+	Value     []byte        // Optional, value to associate with the lock
+	TTL       time.Duration // Optional, expiration ttl associated with the lock
+	RenewLock chan struct{} // Optional, chan used to control and stop the session ttl renewal for the lock
 }
 
 // Locker provides locking mechanism on top of the store.
 // Similar to `sync.Lock` except it may return errors.
 type Locker interface {
-	Lock() (<-chan struct{}, error)
+	Lock(stopChan chan struct{}) (<-chan struct{}, error)
 	Unlock() error
 }