Add boolean rule to README & remove unnecessary ternary

README.md

@@ -109,6 +109,7 @@ V::lang('ar');
  * `accepted` - Checkbox or Radio must be accepted (yes, on, 1, true)
  * `numeric` - Must be numeric
  * `integer` - Must be integer number
+ * `boolean` - Must be boolean
  * `array` - Must be array
  * `length` - String must be certain length
  * `lengthBetween` - String must be between given lengths

src/Valitron/Validator.php

@@ -653,7 +653,7 @@ class Validator
      */
     protected function validateBoolean($field, $value)
     {
-        return (is_bool($value)) ? true : false;
+        return is_bool($value);
     }
 
     /**