JED 1.6.0+ - Disable hostile and/or peaceful mob spawns

{
    "dimensions":
    [
        {
            "dim": 8,
            "dimensiontype": {
                "id": 8,
                "name": "Flat, Creative",
                "suffix": "_dim8",
                "keeploaded": false,
                "worldprovider": "WorldProviderSurfaceJED"
            },
            "worldinfo_onetime": {
                "generatorName": "flat",
                "generatorOptions": "3;minecraft:bedrock,63*minecraft:dirt,minecraft:grass;1",
                "RandomSeed": "testing",
                "DayTime": 18000,
                "Difficulty": 3,
                "GameType": 1,
                "SpawnX": 256,
                "SpawnZ": 256,
                "GameRules": {
                    "doDaylightCycle": "false",
                    "doWeatherCycle": "false"
                }
            },
            "jed": {
                "CanSpawnHostiles": false,
                "CanSpawnPeacefulMobs": false
            }
        }
    ]
}