Work on evaluation

tests/integration/numerical_operations_tests.cpp

@@ -0,0 +1,12 @@
+#ifdef TESTS_BUILD
+#include <catch.hpp>
+#include "../src/Script.hpp"
+
+TEST_CASE( "Simple addition", "[integration]" ) {
+    Script script = Script::Create("1 + 5");
+    REQUIRE(!script.Diagnostics -> HasErrors());
+    script.Evaluate();
+    auto lastValue = script.GetLastValue();
+    REQUIRE(*any_cast<long>(lastValue) == 6);
+}
+#endif