Flinkster: Filter for fuel type

[dennispost]

Add possibility to filter for petrol, diesel or electric cars

Possible query syntax:

flinksterCars {
  attributes {
    transmissionType
    fuel (fuelType = "electric")
    fillLevel
  }
}

Petrol powered car:

{
  "name": "Opel Corsa",
  "attributes": {
    "transmissionType": "manual",
    "fuel": "petrol",
    "fillLevel": 75
  }
}

Electric powered car:

{
  "name": "Citroën C-Zero",
  "attributes": {
    "transmissionType": "automatic",
    "fuel": "electric",
    "fillLevel": 68
  }
}