func ParseFromRequest(req *http.Request, extractor Extractor, keyFunc jwt.Keyfunc) (token *jwt.Token, err error) {
	return ParseFromRequestWithClaims(req, extractor, jwt.MapClaims{}, keyFunc)
}
Extract and parse a JWT token from an HTTP request.
This behaves the same as Parse, but accepts a request and an extractor
instead of a token string.  The Extractor interface allows you to define
the logic for extracting a token.  Several useful implementations are provided.
package request
import (
	"github.com/dgrijalva/jwt-go"
	"net/http"
)