move core result into core utils

Signed-off-by: Jason Volk <jason@zemos.net>

src/core/utils/mod.rs

@@ -10,6 +10,7 @@ pub mod json;
 pub mod math;
 pub mod mutex_map;
 pub mod rand;
+pub mod result;
 pub mod set;
 pub mod stream;
 pub mod string;