Move genericclioptions.IOStreams into genericiooptions.IOStreams

Currently, `genericclioptions` package imports `resource` package in cli-runtime
(i.e. builder_flags uses builder object in resource). Therefore, it is not allowed
that `resource` can import any package in `genericclioptions`(due to disallowed import cycles).
It is already reasonable burden except `genericclioptions.IOStreams`.

There are some cases we want to raise a warning to user in builder but
it can not be achieved due to resource package can not depend on
IOStreams. Since IOStreams solely contains go primitives, this PR
deprecates `genericclioptions.IOStreams` and adds `genericiooptions.IOStreams`.

Thanks to that, that will add capability of using IOStreams also in
builders, etc.

staging/src/k8s.io/cli-runtime/pkg/genericclioptions/io_options.go

@@ -24,6 +24,7 @@ import (
 
 // IOStreams provides the standard names for iostreams.  This is useful for embedding and for unit testing.
 // Inconsistent and different names make it hard to read and review code
+// DEPRECATED: use genericiooptions.IOSTREAMS
 type IOStreams struct {
 	// In think, os.Stdin
 	In io.Reader
@@ -34,6 +35,7 @@ type IOStreams struct {
 }
 
 // NewTestIOStreams returns a valid IOStreams and in, out, errout buffers for unit tests
+// DEPRECATED: use genericiooptions.NewTestIOStreams
 func NewTestIOStreams() (IOStreams, *bytes.Buffer, *bytes.Buffer, *bytes.Buffer) {
 	in := &bytes.Buffer{}
 	out := &bytes.Buffer{}
@@ -47,6 +49,7 @@ func NewTestIOStreams() (IOStreams, *bytes.Buffer, *bytes.Buffer, *bytes.Buffer)
 }
 
 // NewTestIOStreamsDiscard returns a valid IOStreams that just discards
+// DEPRECATED: use genericiooptions.NewTestIOStreamsDiscard
 func NewTestIOStreamsDiscard() IOStreams {
 	in := &bytes.Buffer{}
 	return IOStreams{

staging/src/k8s.io/cli-runtime/pkg/genericiooptions/io_options.go

@@ -0,0 +1,56 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+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.
+*/
+
+package genericiooptions
+
+import (
+	"bytes"
+	"io"
+)
+
+// IOStreams provides the standard names for iostreams.  This is useful for embedding and for unit testing.
+// Inconsistent and different names make it hard to read and review code
+type IOStreams struct {
+	// In think, os.Stdin
+	In io.Reader
+	// Out think, os.Stdout
+	Out io.Writer
+	// ErrOut think, os.Stderr
+	ErrOut io.Writer
+}
+
+// NewTestIOStreams returns a valid IOStreams and in, out, errout buffers for unit tests
+func NewTestIOStreams() (IOStreams, *bytes.Buffer, *bytes.Buffer, *bytes.Buffer) {
+	in := &bytes.Buffer{}
+	out := &bytes.Buffer{}
+	errOut := &bytes.Buffer{}
+
+	return IOStreams{
+		In:     in,
+		Out:    out,
+		ErrOut: errOut,
+	}, in, out, errOut
+}
+
+// NewTestIOStreamsDiscard returns a valid IOStreams that just discards
+func NewTestIOStreamsDiscard() IOStreams {
+	in := &bytes.Buffer{}
+	return IOStreams{
+		In:     in,
+		Out:    io.Discard,
+		ErrOut: io.Discard,
+	}
+}