arrays of objects

This doesn't seem to work right with `graphql` or `proto` with this:

```json
{
"name": "Taylor Lindgren",
"id": "0060c905-1e2f-42c9-8ae2-3c3f3bf88221",
"username": "Taylor_Lindgren",
"email": "Taylor_Lindgren@isac.biz",
"address": {
"street": "Rosella Parkway",
"suite": "Apt. 665",
"city": "Lake Georgianna",
"zipcode": "57812-6730",
"geo": {
"lat": -37.8063,
"lng": -178.4724
}
},
"phone": "1-510-658-2754 x6482",
"website": "https://isac.biz",
"posts": [
{
"id": "1b4bd7b6-8899-4504-aa9a-27cf31b8c77d",
"title": "My First Post",
"date": "2019-05-26T03:27:46Z"
}
]
}
```

`posts` shows like this in `graphql`:

```graphql
type User {
id: String
email: String
username: String
posts: [Object]
}
```

and this in `proto`:

```proto
message User {
string id = 1;
string email = 2;
string username = 3;
repeated undefined posts = 4;
}
```

No files or tests are named. Start by reproducing the sample JSON through the GraphQL and proto generation paths, then trace how the nested posts array is typed; done means both outputs represent the array of objects correctly rather than using Object or undefined.

Written by the indexing model from the issue text.