Add a black box local cluster harness (#3028)

Integration test harness for the network.

tests/local_cluster.rs

@@ -0,0 +1,40 @@
+extern crate solana;
+
+use solana::cluster_tests;
+use solana::local_cluster::LocalCluster;
+
+#[test]
+fn test_spend_and_verify_all_nodes_1() -> () {
+    solana_logger::setup();
+    let num_nodes = 1;
+    let local = LocalCluster::new(num_nodes, 10_000, 100);
+    cluster_tests::spend_and_verify_all_nodes(
+        &local.entry_point_info,
+        &local.funding_keypair,
+        num_nodes,
+    );
+}
+
+#[test]
+fn test_spend_and_verify_all_nodes_2() -> () {
+    solana_logger::setup();
+    let num_nodes = 2;
+    let local = LocalCluster::new(num_nodes, 10_000, 100);
+    cluster_tests::spend_and_verify_all_nodes(
+        &local.entry_point_info,
+        &local.funding_keypair,
+        num_nodes,
+    );
+}
+
+#[test]
+fn test_spend_and_verify_all_nodes_3() -> () {
+    solana_logger::setup();
+    let num_nodes = 3;
+    let local = LocalCluster::new(num_nodes, 10_000, 100);
+    cluster_tests::spend_and_verify_all_nodes(
+        &local.entry_point_info,
+        &local.funding_keypair,
+        num_nodes,
+    );
+}