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/fatih/structs/structs.go

@@ -530,15 +530,22 @@ func (s *Struct) nested(val reflect.Value) interface{} {
 			finalVal = m
 		}
 	case reflect.Map:
-		v := val.Type().Elem()
-		if v.Kind() == reflect.Ptr {
-			v = v.Elem()
+		// get the element type of the map
+		mapElem := val.Type()
+		switch val.Type().Kind() {
+		case reflect.Ptr, reflect.Array, reflect.Map,
+			reflect.Slice, reflect.Chan:
+			mapElem = val.Type().Elem()
+			if mapElem.Kind() == reflect.Ptr {
+				mapElem = mapElem.Elem()
+			}
 		}
 
 		// only iterate over struct types, ie: map[string]StructType,
 		// map[string][]StructType,
-		if v.Kind() == reflect.Struct ||
-			(v.Kind() == reflect.Slice && v.Elem().Kind() == reflect.Struct) {
+		if mapElem.Kind() == reflect.Struct ||
+			(mapElem.Kind() == reflect.Slice &&
+				mapElem.Elem().Kind() == reflect.Struct) {
 			m := make(map[string]interface{}, val.Len())
 			for _, k := range val.MapKeys() {
 				m[k.String()] = s.nested(val.MapIndex(k))

vendor/github.com/fatih/structs/tags.go

@@ -5,7 +5,7 @@ import "strings"
 // tagOptions contains a slice of tag options
 type tagOptions []string
 
-// Has returns true if the given optiton is available in tagOptions
+// Has returns true if the given option is available in tagOptions
 func (t tagOptions) Has(opt string) bool {
 	for _, tagOpt := range t {
 		if tagOpt == opt {