Update dependencies to K8s 1.8

vendor/golang.org/x/text/cases/fold.go

@@ -18,7 +18,15 @@ func (t *caseFolder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err
 	return c.ret()
 }
 
-func makeFold(o options) transform.Transformer {
+func (t *caseFolder) Span(src []byte, atEOF bool) (n int, err error) {
+	c := context{src: src, atEOF: atEOF}
+	for c.next() && isFoldFull(&c) {
+		c.checkpoint()
+	}
+	return c.retSpan()
+}
+
+func makeFold(o options) transform.SpanningTransformer {
 	// TODO: Special case folding, through option Language, Special/Turkic, or
 	// both.
 	// TODO: Implement Compact options.