Smarter expectations using with()

``` php
->expect('myMethod')->twice()->with('foo')
```

Will expect `myMethod('foo')` is called twice. However,

``` php
->expect('myMethod')->with('foo')->twice()
```

Will allow myMethod to be called with any arguments zero or more times, but `myMethod('foo')` must be called twice in that subset of calls.

Stringing multiple combinations together:

``` php
->expect('myMethod')->with('foo')->twice()->with('bar')->never()
```

`myMethod` can be called any number of times with any arguments but it `myMethod('foo')` must be called twice and `myMethod('bar')` never called.