Update readme

Author: usox

README.md

@@ -1,21 +1,20 @@
 [![Build Status](https://travis-ci.org/usox/hackmock.svg?branch=master)](https://travis-ci.org/usox/hackmock)
 
-# HackMock - in development...
+# HackMock
 
 Creating mock objects for hacklang - yes, seriously.
 
-It's strongly recommended not to use this in any sort of production environment.
+## Note
+
+Due to the use of `eval`, hackmock may stop working in future hhvm versions.
 
 ## What works?
 - Strict mode
-- Creating mocks of interfaces
+- Creating mocks of interfaces and concrete classes
 - Defining basic method expectations (parameter validation, return value definition)
 
 ## What does not work?
-- Everything else.
-
-## But I want to try
-Ok.
+- Everything else, especially rare and/or untested cases involving generics, etc.
 
 ```php
 use function Usox\HackMock\{mock, prospect};
@@ -26,7 +25,7 @@ class SomethingTest extends \Usox\HackMock\HackMock {
     $my_fine_class = mock(SomeInterface::class);
 
     prospect($my_fine_class, 'someMethodName')
-      ->times(1)
+      ->once()
       ->andReturn('some-fine-value');
 
     prospect($my_fine_class, 'someOtherMethodName')