json key filter
import elek from 'elek'
const object = {
"test1": {
"color": "red"
},
"test4": {
"test5": {
"color": "blue"
}
},
"test7": {
"test8": {
"test9": {
"color": "green"
}
}
}
}
elek(object, "color").map(_ => _.color) // ['red', 'blue', 'green']