{
  "$schema": "http://json-schema.org/draft-04/schema",
  "type":"object",
  "properties":{
    "ref":{
      "description": "Github branch/tag",
      "type": "string",
      "maxLength": 255
    },
    "after": {
      "type":"string",
      "title": "Github push (after commit)",
      "maxLength": 250
    },
    "deleted": {
      "type":"boolean"
    },
    "repository": {
      "$ref": "#/definitions/repository"
    }
  },
  "additionalProperties" : true,
  "required" : ["repository"],
  "definitions": {
    "repository": {
      "type": "object",
      "properties": {
        "name": {
          "description": "Name of the repository",
          "maxLength": 100
        },
        "owner": {
          "$ref": "#/definitions/owner"
        }
      },
      "additionalProperties": true,
      "required": ["name", "owner"]
    },
    "owner": {
      "type": "object",
      "oneOf": [
        {
          "properties": {
            "name": {
              "description": "Name of the repository owner",
              "maxLength": 100
            }
          },
          "required": ["name"],
          "additionalProperties": true
        },
        {
          "properties": {
            "login": {
              "description": "Name of the repository owner",
              "maxLength": 100
            }
          },
          "required": ["login"],
          "additionalProperties": true
        }
      ]
    }
  }
}

{
  "$schema": "http://json-schema.org/draft-04/schema",
  "type":"object",
  "properties":{
    "ref":{
      "description": "Github branch/tag",
      "type": "string",
      "maxLength": 255
    },
    "after": {
      "type":"string",
      "title": "Github push (after commit)",
      "maxLength": 250
    },
    "deleted": {
      "type":"boolean"
    },
    "repository": {
      "$ref": "#/definitions/repository"
    }
  },
  "additionalProperties" : true,
  "required" : ["repository"],
  "definitions": {
    "repository": {
      "type": "object",
      "properties": {
        "name": {
          "description": "Name of the repository",
          "maxLength": 100
        },
        "owner": {
          "$ref": "#/definitions/owner"
        }
      },
      "additionalProperties": true,
      "required": ["name", "owner"]
    },
    "owner": {
      "type": "object",
      "anyOf": [
        {
          "properties": {
            "name": {
              "description": "Name of the repository owner",
              "maxLength": 100
            }
          },
          "required": ["name"],
          "additionalProperties": true
        },
        {
          "properties": {
            "login": {
              "description": "Name of the repository owner",
              "maxLength": 100
            }
          },
          "required": ["login"],
          "additionalProperties": true
        }
      ]
    }
  }
}

Allow anyOf login / name to get owner
Allow anyOf login / name to get owner

Allow anyOf login / name to get owner