Fixed validation rule value

src/Mixin.js

@@ -16,7 +16,7 @@ var convertValidationsToObject = function (validations) {
       if (args.length > 1) {
         throw new Error('Formsy does not support multiple args on string validations. Use object format of validations instead.');
       }
-      validations[validateMethod] = args[0] || true;
+      validations[validateMethod] = args[0];
       return validations;
     }, {});
 

src/main.js

@@ -115,7 +115,7 @@ Formsy.Form = React.createClass({
       var component = this.inputs[name];
       var args = [{
         _isValid: !(name in errors),
-        _serverError: errors[name]
+        _validationError: errors[name]
       }];
       component.setState.apply(component, args);
     }.bind(this));