Support Object type

[krhubert]

TODO:

• write tests (manual tests passes even with nested array objects)

{
  "message": ["a", "b"],
  "myobj": {
    "x1": "string",
    "x2": 1 
  },
  "myobjarr": [{
    "x1": {
      "x1": "string",
      "x2": 1 
    },
    "x2": 1 
  }]
}

• @NicolasMahe can you help with schema.json (how to tell that object type must be definitions/parameters - "$ref": "#/definitions/parameters" ?

• figure out better name for defParametersMapToService

• Object map[string]*Parameter hash:"name:7" - i don't like that hash with number 7 is inside type, move object to last position in struct

• better error messages for nested objects in parameter warning.

[antho1404]

I was working on that feature too yesterday evening, I have few differences:

• not using the defParametersMapToService function
• not doing the loop in the validation of the object but instead use the validateParametersSchema function
• I had to change the signature of validateType with a list of warnings instead of one warning only

If you want to have a look at it either if fine to merge or to help you work on this PR.

My version: #696

[krhubert]

Close in favor of #696, as it's more complete