Add vendor files for spf13/viper

vendor/github.com/spf13/afero/const_bsds.go

@@ -0,0 +1,22 @@
+// Copyright © 2016 Steve Francia <spf@spf13.com>.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build darwin openbsd freebsd netbsd dragonfly
+
+package afero
+
+import (
+	"syscall"
+)
+
+const BADFD = syscall.EBADF