cluster: configurable session TTL for the leader elector

cluster/etcd_elector_test.go

@@ -57,15 +57,16 @@ func TestEtcdElector(t *testing.T) {
 		election = "/election/"
 		id1      = "e1"
 		id2      = "e2"
+		ttl      = 5
 	)
 
 	e1, err := newEtcdLeaderElector(
-		ctx, id1, election, etcdCfg,
+		ctx, id1, election, ttl, etcdCfg,
 	)
 	require.NoError(t, err)
 
 	e2, err := newEtcdLeaderElector(
-		ctx, id2, election, etcdCfg,
+		ctx, id2, election, ttl, etcdCfg,
 	)
 	require.NoError(t, err)