Update README.md
Merge pull request #235 from ndacosta/patch-1

Update README.md with a couple of minor english grammar mistakes, thanks to @ndacosta.
Typo.
Refactoring to remove duplicate code.
Refactoring to remove duplicate code.
Optimization.
Typo.
Call closure directly instead of using call_user_func().
Close #212.
Optimize mock controller and invoker.
Refactoring.
Close #217 and  is now the mock in the mock controller with PHP ≥ 5.4.
Close #240.
Add unit test about phpFunction asserter.
Typo.
Check if a closure is bindable before bind it to the mock.
It's now possible to disable auto binding to mock in a mock controller.
Typo.
Handle now correctly closure in the global scope.
It's now possible to get the last asserted exception with the property ->exception in a test class.