Match asset code and issuer in ticker market data

As the blog post mentions, the list of assets is accessible at https://ticker.stellar.org/assets.json. Assets have code and issuer fields. For example:

    "assets": [
        {
            "code": "CSM",
            "issuer": "GCGBSZ3DSSH6PRHCOD4JXFNNZXCTKBDFRT4JR2HIAC6FQZU4YK7GPHEX",
            "type": "credit_alphanum4",
            "num_accounts": 17,
            "auth_required": false,
            "auth_revocable": false,
            "amount": 999999.9999994,
            "asset_controlled_by_domain": true,
            "anchor_asset": "",
            "anchor_asset_type": "",
            "display_decimals": 7,
            "name": "City States Medieval",
            "desc": "City States Medieval share",
            "conditions": "Share representing ownership in the game City States: Medieval",
            "is_asset_anchored": false,
            "fixed_number": 0,
            "max_number": 0,
            "is_unlimited": false,
            "redemption_instructions": "",
            "collateral_addresses": [],
            "collateral_address_signatures": [],
            "countries": "",
            "status": "live",
            "issuer_detail": {
                "public_key": "GCGBSZ3DSSH6PRHCOD4JXFNNZXCTKBDFRT4JR2HIAC6FQZU4YK7GPHEX",
                "name": "",
                "url": "",
                "toml_url": "https://stratemacy.com/.well-known/stellar.toml",
                "federation_server": "",
                "auth_server": "",
                "transfer_server": "",
                "web_auth_endpoint": "",
                "deposit_server": "",
                "org_twitter": ""
            },
            "last_valid": "2019-10-08T12:00:15Z"
        },