A Quick and Dirty Rust wrapper for cv19api

Wraps cv19api, a weekend project on Covid by the Lancaster Beer & Code collective.

Handles the following endpoints and returns an Ok(Response) for each. Each Endpoint has its own response type rather than making the trust and region fields optional.

```bash /deaths

{
    "data": [
        {
            "date": "2020-04-14",
            "deaths": 113
        },
    ...
    ]
    ,
    "metaData": {
        "recordedOnTo": "2020-04-15",
        "from": "2020-03-16",
        "to": "2020-04-15",
        "recordedOnFrom": "2020-01-01"
    }
}

```

```bash /deaths/trusts

    {
    "data": [
        {
            "date": "2020-04-14",
            "trust": "AIREDALE NHS FOUNDATION TRUST",
            "deaths": 0
        },
    ...
    ]
    ,
    "metaData": {
        "recordedOnTo": "2020-04-15",
        "from": "2020-03-16",
        "to": "2020-04-15",
        "recordedOnFrom": "2020-01-01"
    }
}

```

```bash /deaths/regions

    {
    "data": [
        {
            "date": "2020-04-14",
            "region": "EAST_OF_ENGLAND",
            "deaths": 41
        },
    ...
    ]
    ,
    "metaData": {
        "recordedOnTo": "2020-04-15",
        "from": "2020-03-16",
        "to": "2020-04-15",
        "recordedOnFrom": "2020-01-01"
    }
}

```

Example

Quick and dirty usage

cargo run --example get_deaths
cargo run --example get_deaths_by_region
cargo run --example get_deaths_by_trust