Fix failing issues with vendoring as well as compiling

Something within golang.org/x/sys messed up and it doesn't help that we
have three different projects using different versions.

This vendor update specifies a golang.org/x/sys as well as fixes the
previous compiling issues with Windows/Linux/macOS builds.

See issue:

```sh
gox -osarch="darwin/amd64 linux/amd64 linux/arm windows/amd64"
-output="bin/kompose-{{.OS}}-{{.Arch}}" -ldflags="-w -X
github.com/kubernetes/kompose/pkg/version.GITCOMMIT=42e7f0e"
Number of parallel builds: 1
-->   windows/amd64: github.com/kubernetes/kompose
-->     linux/amd64: github.com/kubernetes/kompose
-->    darwin/amd64: github.com/kubernetes/kompose
-->       linux/arm: github.com/kubernetes/kompose
1 errors occurred:
--> windows/amd64 error: exit status 2
Stderr: #
github.com/kubernetes/kompose/vendor/golang.org/x/crypto/ssh/terminal
vendor/golang.org/x/crypto/ssh/terminal/util_windows.go:42: undefined:
windows.ENABLE_ECHO_INPUT
vendor/golang.org/x/crypto/ssh/terminal/util_windows.go:42: undefined:
windows.ENABLE_PROCESSED_INPUT
vendor/golang.org/x/crypto/ssh/terminal/util_windows.go:42: undefined:
windows.ENABLE_LINE_INPUT
vendor/golang.org/x/crypto/ssh/terminal/util_windows.go:42: undefined:
windows.ENABLE_PROCESSED_OUTPUT
vendor/golang.org/x/crypto/ssh/terminal/util_windows.go:43: undefined:
windows.SetConsoleMode
vendor/golang.org/x/crypto/ssh/terminal/util_windows.go:62: undefined:
windows.SetConsoleMode
vendor/golang.org/x/crypto/ssh/terminal/util_windows.go:67: undefined:
windows.ConsoleScreenBufferInfo
vendor/golang.org/x/crypto/ssh/terminal/util_windows.go:68: undefined:
windows.GetConsoleScreenBufferInfo
vendor/golang.org/x/crypto/ssh/terminal/util_windows.go:91: undefined:
windows.ENABLE_ECHO_INPUT
vendor/golang.org/x/crypto/ssh/terminal/util_windows.go:92: undefined:
windows.ENABLE_PROCESSED_INPUT
vendor/golang.org/x/crypto/ssh/terminal/util_windows.go:92: too many
errors
```

vendor/github.com/spf13/pflag/string_slice.go

@@ -3,12 +3,9 @@ package pflag
 import (
 	"bytes"
 	"encoding/csv"
-	"fmt"
 	"strings"
 )
 
-var _ = fmt.Fprint
-
 // -- stringSlice Value
 type stringSliceValue struct {
 	value   *[]string
@@ -39,7 +36,7 @@ func writeAsCSV(vals []string) (string, error) {
 		return "", err
 	}
 	w.Flush()
-	return strings.TrimSuffix(b.String(), fmt.Sprintln()), nil
+	return strings.TrimSuffix(b.String(), "\n"), nil
 }
 
 func (s *stringSliceValue) Set(val string) error {