Use default rust directory structure for tests

tests/if_block.rs

@@ -0,0 +1,26 @@
+extern crate rhai;
+
+use rhai::Engine;
+
+#[test]
+fn test_if() {
+    let mut engine = Engine::new();
+
+    if let Ok(result) = engine.eval::<i64>("if true { 55 }") {
+        assert_eq!(result, 55);
+    } else {
+        assert!(false);
+    }
+
+    if let Ok(result) = engine.eval::<i64>("if false { 55 } else { 44 }") {
+        assert_eq!(result, 44);
+    } else {
+        assert!(false);
+    }
+
+    if let Ok(result) = engine.eval::<i64>("if true { 55 } else { 44 }") {
+        assert_eq!(result, 55);
+    } else {
+        assert!(false);
+    }
+}