Closes #1583 by setting up the datadir for the wallet gtest.

src/wallet/gtest/test_wallet.cpp

@@ -11,6 +11,8 @@
 #include "zcash/Note.hpp"
 #include "zcash/NoteEncryption.hpp"
 
+#include <boost/filesystem.hpp>
+
 using ::testing::Return;
 
 ZCJoinSplit* params = ZCJoinSplit::Unopened();
@@ -178,6 +180,13 @@ CWalletTx GetValidSpend(const libzcash::SpendingKey& sk,
     return wtx;
 }
 
+TEST(wallet_tests, setup_datadir_location_run_as_first_test) {
+    // Get temporary and unique path for file.
+    boost::filesystem::path pathTemp = boost::filesystem::temp_directory_path() / boost::filesystem::unique_path();
+    boost::filesystem::create_directories(pathTemp);
+    mapArgs["-datadir"] = pathTemp.string();
+}
+
 TEST(wallet_tests, note_data_serialisation) {
     auto sk = libzcash::SpendingKey::random();
     auto wtx = GetValidReceive(sk, 10, true);