assert.include: Added support for needles of 'Object' type.

"Assert.include: Added support for needles of 'Object' type."

Hey, Currently assert.include(needle, haystack) doesnot support needle of Object type. Particularly, useful for asserting presence of a 'hash' in a array of hashes.

It throws error on 
```
> assert.include
[Function]
> haystack = [{1:2},3]
[ { '1': 2 }, 3 ]
> needle = {1:2}
{ '1': 2 }
> assert.include(needle,haystack)
Error: include expected needle to be found in haystack
- needle: {"1":2}
haystack: [{"1":2},3]
    at error (node_modules/assertive/lib/assertive.js:443:12)
    at Object.assert.include (node_modules/assertive/lib/assertive.js:186:15)
    at repl:1:9
    at REPLServer.self.eval (repl.js:110:21)
    at Interface.<anonymous> (repl.js:239:12)
    at Interface.EventEmitter.emit (events.js:95:17)
    at Interface._onLine (readline.js:202:10)
    at Interface._line (readline.js:531:8)
    at Interface._ttyWrite (readline.js:760:14)
    at ReadStream.onkeypress (readline.js:99:10)
```

If there is any other way around. Kindly tell. Pardon my ignorance.

Otherwise, I tried to add the functionality myself. This PR is for the same. After adding this PR, assert.include checks presence of needle ( 'Object' type ) in haystack ('Array' type) as well.

```
> assert.include
[Function]
> haystack = [{1:2},3]
[ { '1': 2 }, 3 ]
> needle = {1:2}
{ '1': 2 }
> assert.include(needle,haystack)
undefined
>
```

I will add the test-cases once you agree for adding this functionality.