Cluster test: basic failover unit added.

tests/cluster/tests/02-failover.tcl

+# Check the basic monitoring and failover capabilities.
+
+source "../tests/includes/init-tests.tcl"
+
+test "Create a 5 nodes cluster" {
+    create_cluster 5 5
+}
+
+test "Cluster is up" {
+    assert_cluster_state ok
+}
+
+test "Cluster is writable" {
+    cluster_write_test 0
+}
+
+test "Instance #5 is a slave" {
+    assert {[RI 5 role] eq {slave}}
+}
+
+test "Killing one master node" {
+    kill_instance redis 0
+}
+
+test "Cluster should eventually be up again" {
+    assert_cluster_state ok
+}
+
+test "Cluster is writable" {
+    cluster_write_test 1
+}
+
+test "Instance #5 is now a master" {
+    assert {[RI 5 role] eq {master}}
+}