db_index test -> the index creation is tested for now

tests/db_index.cpp

@@ -0,0 +1,16 @@
+#include <iostream>
+
+#include "storage/indexes/index.hpp"
+
+using std::cout;
+using std::endl;
+
+using StringUniqueKeyAsc = UniqueKeyAsc<std::string>;
+
+int main(void)
+{
+    // index creation
+    auto index = std::make_shared<Index<StringUniqueKeyAsc, std::string>>();
+
+    return 0;
+}