non-exported struct fields are being exported

[tcarreira]

Describe the bug
If I have not-exported fields on a struct, it gets exported as a json example. It should stay hidden

To Reproduce

If you have this code:

// TestStruct Test Struct
type TestStruct struct {
	tableName    struct{}
	anotherField string
	ID           uint64 `json:"-"`
	Name         string `json:"name"`
	Age          int    `json:"age"`
}

// TestFunction Test
// ---
// @Summary Test Function
// @Description Test non-exported fields
// @Produce json
// @Success 200 {object} TestStruct "Test Struct"
// @Router /test [get]
func TestFunction() {}

We get the struct TestStruct with example :

{
  "age": 0,
  "anotherField": "string",
  "name": "string",
  "tableName": {}
}

Expected behavior
we should get:

{
  "age": 0,
  "name": "string"
}

Screenshots

Your swag version

$ swag -v
swag version v1.6.5

Your go version

$ go version
go version go1.14.1 linux/amd64

Additional context
The fields disappear it I explicitly disable them with a json tag:

// TestStruct Test Struct
type TestStruct struct {
	tableName    struct{} `json:"-"`
	anotherField string   `json:"-"`
	ID           uint64   `json:"-"`
	Name         string   `json:"name"`
	Age          int      `json:"age"`
}

PS
Point me in the right direction, and I may get some time to submit a PR