The produced patch is not the minimal one

Hi,

Consider the following example:

``` javascript
→  jsondiff <(echo '[{"foo": 1, "bar": 2}]') <(echo '[{"foo": 2, "bar": 2}]') | jq .
[
  {
    "path": "/0",
    "value": {
      "foo": 2,
      "bar": 2
    },
    "op": "replace"
  }
]
```

I think the result should be:

``` javascript
[
  {
    "path": "/0/foo",
    "value": 2,
    "op": "replace"
  }
]
```
