config file looks like:

{
    "embedding": {
	"embedodir": "",
	"sg": 1,
	"window": 15,
	"size": 250,
	"workers": 4
    },

    "topic_model":  {
	"mallet_path": "",
	"num_topics": 5,
	"tmodir": "",
    },

    "mongo_credentials": {
        "database": "",
        "host": "",
        "port": "",
        "user": "",
        "pwd": ""
    }
}