opts: remove unused RuntimeOpt

This type was copied from the daemone in 8b725e10e7,
but actually unused on the CLI side, so we can remove it here.

The original code is still present in the daemon at
https://github.com/moby/moby/blob/7b9275c0da707b030e62c96b679a976f31f929d3/opts/runtime.go

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

opts/runtime.go

@@ -1,79 +0,0 @@
-package opts
-
-import (
-	"fmt"
-	"strings"
-
-	"github.com/docker/docker/api/types"
-)
-
-// RuntimeOpt defines a map of Runtimes
-type RuntimeOpt struct {
-	name             string
-	stockRuntimeName string
-	values           *map[string]types.Runtime
-}
-
-// NewNamedRuntimeOpt creates a new RuntimeOpt
-func NewNamedRuntimeOpt(name string, ref *map[string]types.Runtime, stockRuntime string) *RuntimeOpt {
-	if ref == nil {
-		ref = &map[string]types.Runtime{}
-	}
-	return &RuntimeOpt{name: name, values: ref, stockRuntimeName: stockRuntime}
-}
-
-// Name returns the name of the NamedListOpts in the configuration.
-func (o *RuntimeOpt) Name() string {
-	return o.name
-}
-
-// Set validates and updates the list of Runtimes
-func (o *RuntimeOpt) Set(val string) error {
-	parts := strings.SplitN(val, "=", 2)
-	if len(parts) != 2 {
-		return fmt.Errorf("invalid runtime argument: %s", val)
-	}
-
-	parts[0] = strings.TrimSpace(parts[0])
-	parts[1] = strings.TrimSpace(parts[1])
-	if parts[0] == "" || parts[1] == "" {
-		return fmt.Errorf("invalid runtime argument: %s", val)
-	}
-
-	parts[0] = strings.ToLower(parts[0])
-	if parts[0] == o.stockRuntimeName {
-		return fmt.Errorf("runtime name '%s' is reserved", o.stockRuntimeName)
-	}
-
-	if _, ok := (*o.values)[parts[0]]; ok {
-		return fmt.Errorf("runtime '%s' was already defined", parts[0])
-	}
-
-	(*o.values)[parts[0]] = types.Runtime{Path: parts[1]}
-
-	return nil
-}
-
-// String returns Runtime values as a string.
-func (o *RuntimeOpt) String() string {
-	var out []string
-	for k := range *o.values {
-		out = append(out, k)
-	}
-
-	return fmt.Sprintf("%v", out)
-}
-
-// GetMap returns a map of Runtimes (name: path)
-func (o *RuntimeOpt) GetMap() map[string]types.Runtime {
-	if o.values != nil {
-		return *o.values
-	}
-
-	return map[string]types.Runtime{}
-}
-
-// Type returns the type of the option
-func (o *RuntimeOpt) Type() string {
-	return "runtime"
-}