Skip Intercepted Header test for go <1.6

Signed-off-by: Thibault Jamet <tjamet@users.noreply.github.com>

context_test.go

@@ -13,6 +13,8 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"reflect"
+	"runtime"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -1389,6 +1391,12 @@ func (i interceptedWriter) WriteHeader(code int) {
 }
 
 func TestInterceptedHeader(t *testing.T) {
+	if strings.HasPrefix(runtime.Version(), "go1.") {
+		v, err := strconv.Atoi(strings.SplitAfterN(runtime.Version(), ".", 2)[1])
+		if err != nil || v < 7 {
+			t.Skipf("This test is relying on httptest.ResponseRecorder.Result not implementein version %s", runtime.Version())
+		}
+	}
 	w := httptest.NewRecorder()
 	c, r := CreateTestContext(w)