Add a source file for unit test utils.

src/test/testutil.cpp

@@ -0,0 +1,3 @@
+// Copyright (c) 2009-2016 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.

src/test/testutil.h

@@ -0,0 +1,11 @@
+// Copyright (c) 2009-2016 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+/**
+ * Utility functions shared by unit tests
+ */
+#ifndef BITCOIN_TEST_TESTUTIL_H
+#define BITCOIN_TEST_TESTUTIL_H
+
+#endif // BITCOIN_TEST_TESTUTIL_H