clientv3: Move to client/v3 (just file move)

Mechanical:
% git mv clientv3 client/v3
% git mv client/mock client/v3/

client/v3/namespace/util_test.go

@@ -0,0 +1,75 @@
+// Copyright 2017 The etcd 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 namespace
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestPrefixInterval(t *testing.T) {
+	tests := []struct {
+		pfx string
+		key []byte
+		end []byte
+
+		wKey []byte
+		wEnd []byte
+	}{
+		// single key
+		{
+			pfx: "pfx/",
+			key: []byte("a"),
+
+			wKey: []byte("pfx/a"),
+		},
+		// range
+		{
+			pfx: "pfx/",
+			key: []byte("abc"),
+			end: []byte("def"),
+
+			wKey: []byte("pfx/abc"),
+			wEnd: []byte("pfx/def"),
+		},
+		// one-sided range
+		{
+			pfx: "pfx/",
+			key: []byte("abc"),
+			end: []byte{0},
+
+			wKey: []byte("pfx/abc"),
+			wEnd: []byte("pfx0"),
+		},
+		// one-sided range, end of keyspace
+		{
+			pfx: "\xff\xff",
+			key: []byte("abc"),
+			end: []byte{0},
+
+			wKey: []byte("\xff\xffabc"),
+			wEnd: []byte{0},
+		},
+	}
+	for i, tt := range tests {
+		pfxKey, pfxEnd := prefixInterval(tt.pfx, tt.key, tt.end)
+		if !bytes.Equal(pfxKey, tt.wKey) {
+			t.Errorf("#%d: expected key=%q, got key=%q", i, tt.wKey, pfxKey)
+		}
+		if !bytes.Equal(pfxEnd, tt.wEnd) {
+			t.Errorf("#%d: expected end=%q, got end=%q", i, tt.wEnd, pfxEnd)
+		}
+	}
+}