Added an API to extract card legalities.

# GET /legality/:id or GET /legality/:name

Returns JSON data regarding which formats the card is legal in including any restrictions it may have. For example:

`/legality/Braids,%20Cabal%20Minion`
```
{
        "Odyssey Block":{
            "legality":"Legal",
            "conditions": [ ]
        },
        "Legacy":{
            "legality":"Legal",
            "conditions": [ ]
        },
        "Vintage":{
            "legality":"Legal",
            "conditions": [ ]
        },
        "Freeform":{
            "legality":"Legal",
            "conditions": [ ]
        },
        "Prismatic":{
            "legality":"Legal",
            "conditions": [ ]
        },
        "Tribal Wars Legacy":{
            "legality":"Legal",
            "conditions": [ ]
        },
        "Classic":{
            "legality":"Legal",
            "conditions": [ ]
        },
        "Singleton 100":{
            "legality":"Legal",
            "conditions": [ ]
        },
        "Commander":{
            "legality":"Special",
            "conditions":"Banned as Commander"
        }
}
```