Unmarshalling with embedded structs is failing

[badarsebard]

This is a similar issue to what was happening in #142. Tags aren't being managed properly when using embedded structs.

Example from internal/encoding_test.go:
When the Base struct tag is changed from the empty string (such as _id), it fails to be managed correctly with the current version and the ID is lost when calling Convert. This causes the TestNormalize test to fail at line79.

type BaseModel struct {
   ID string `clover:"_id"`
}

type TestStruct struct {
   BaseModel
   IntField    int                    `clover:"int,omitempty"`
   UintField   uint                   `clover:"uint,omitempty"`
   StringField string                 `clover:",omitempty"`
   FloatField  float32                `clover:",omitempty"`
   BoolField   bool                   `clover:",omitempty"`
   TimeField   time.Time              `clover:",omitempty"`
   IntPtr      *int                   `clover:",omitempty"`
   SliceField  []int                  `clover:",omitempty"`
   MapField    map[string]interface{} `clover:",omitempty"`
   Data        []byte                 `clover:",omitempty"`
}

Adding json tags also fails.

The issue is due to how the createRenameMap function iterates through the fields of the struct. I am submitting a PR that adds a recursive call to the function when the field type is anonymous so the fields of embedded structs will be included.

[badarsebard]

Fixed with #152