Add versioning infrastructure in Go

https://github.com/containers/toolbox/pull/318

meson.build

@@ -1,6 +1,6 @@
 project(
   'toolbox',
-  version: '0.0.18',
+  version: '0.0.90',
   license: 'ASL 2.0',
   meson_version: '>= 0.40.0',
 )

src/meson.build

@@ -4,6 +4,7 @@ go_build_wrapper_program = find_program('go-build-wrapper')
 sources = files(
   'toolbox.go',
   'cmd/root.go',
+  'pkg/version/version.go',
 )
 
 if go.found()

src/pkg/version/version.go

@@ -0,0 +1,38 @@
+/*
+ * Copyright © 2019 – 2020 Red Hat Inc.
+ *
+ * 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 version
+
+import "fmt"
+
+// Version is the version of Toolbox
+type Version struct {
+	Major int
+	Minor int
+	Micro int
+}
+
+// CurrentVersion holds the information about current build version
+var CurrentVersion = Version{
+	Major: 0,
+	Minor: 0,
+	Micro: 90,
+}
+
+// GetVersion returns string with the version of Toolbox
+func GetVersion() string {
+	return fmt.Sprintf("%d.%d.%d", CurrentVersion.Major, CurrentVersion.Minor, CurrentVersion.Micro)
+}