Auto merge of #1205 - str4d:1199-key-management, r=str4d

Add support for spending keys to the basic key store

Prerequisite for #1197 and #1199.

src/gtest/test_keystore.cpp

@@ -0,0 +1,29 @@
+#include <gtest/gtest.h>
+
+#include "keystore.h"
+#include "zcash/Address.hpp"
+
+TEST(keystore_tests, store_and_retrieve_spending_key) {
+    CBasicKeyStore keyStore;
+    libzcash::SpendingKey skOut;
+
+    std::set<libzcash::PaymentAddress> addrs;
+    keyStore.GetPaymentAddresses(addrs);
+    EXPECT_EQ(0, addrs.size());
+
+    auto sk = libzcash::SpendingKey::random();
+    auto addr = sk.address();
+
+    // Sanity-check: we can't get a key we haven't added
+    EXPECT_FALSE(keyStore.HaveSpendingKey(addr));
+    EXPECT_FALSE(keyStore.GetSpendingKey(addr, skOut));
+
+    keyStore.AddSpendingKey(sk);
+    EXPECT_TRUE(keyStore.HaveSpendingKey(addr));
+    EXPECT_TRUE(keyStore.GetSpendingKey(addr, skOut));
+    EXPECT_EQ(sk, skOut);
+
+    keyStore.GetPaymentAddresses(addrs);
+    EXPECT_EQ(1, addrs.size());
+    EXPECT_EQ(1, addrs.count(addr));
+}