Update oxy dependency

vendor/github.com/vulcand/oxy/utils/source.go

@@ -6,21 +6,25 @@ import (
 	"strings"
 )
 
-// ExtractSource extracts the source from the request, e.g. that may be client ip, or particular header that
+// SourceExtractor extracts the source from the request, e.g. that may be client ip, or particular header that
 // identifies the source. amount stands for amount of connections the source consumes, usually 1 for connection limiters
 // error should be returned when source can not be identified
 type SourceExtractor interface {
 	Extract(req *http.Request) (token string, amount int64, err error)
 }
 
+// ExtractorFunc extractor function type
 type ExtractorFunc func(req *http.Request) (token string, amount int64, err error)
 
+// Extract extract from request
 func (f ExtractorFunc) Extract(req *http.Request) (string, int64, error) {
 	return f(req)
 }
 
+// ExtractSource extract source function type
 type ExtractSource func(req *http.Request)
 
+// NewExtractor creates a new SourceExtractor
 func NewExtractor(variable string) (SourceExtractor, error) {
 	if variable == "client.ip" {
 		return ExtractorFunc(extractClientIP), nil
@@ -31,17 +35,17 @@ func NewExtractor(variable string) (SourceExtractor, error) {
 	if strings.HasPrefix(variable, "request.header.") {
 		header := strings.TrimPrefix(variable, "request.header.")
 		if len(header) == 0 {
-			return nil, fmt.Errorf("Wrong header: %s", header)
+			return nil, fmt.Errorf("wrong header: %s", header)
 		}
 		return makeHeaderExtractor(header), nil
 	}
-	return nil, fmt.Errorf("Unsupported limiting variable: '%s'", variable)
+	return nil, fmt.Errorf("unsupported limiting variable: '%s'", variable)
 }
 
 func extractClientIP(req *http.Request) (string, int64, error) {
 	vals := strings.SplitN(req.RemoteAddr, ":", 2)
 	if len(vals[0]) == 0 {
-		return "", 0, fmt.Errorf("Failed to parse client IP: %v", req.RemoteAddr)
+		return "", 0, fmt.Errorf("failed to parse client IP: %v", req.RemoteAddr)
 	}
 	return vals[0], 1, nil
 }