*: move version from library to cmd, and generate it

oh dang, I released 0.5.2 and 0.5.3 without correctly setting the
version string :-\
Ideally this "-dev" is attempting to be like the git.
So, ditch the version in the library.

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

Makefile

@@ -82,7 +82,7 @@ CLEAN_FILES += .cli.test .cli.test.tags
 build: $(BUILD)
 
 $(BUILD): $(SOURCE_FILES)
-	go build -mod=vendor -o $(BUILD) $(BUILDPATH)
+	go build -ldflags="-X 'main.Version=$(shell git describe --always --dirty)'" -mod=vendor -o $(BUILD) $(BUILDPATH)
 
 install.tools:
 	@go install -u github.com/fatih/color@latest ; \

cmd/gomtree/main.go

@@ -14,9 +14,12 @@ import (
 	"github.com/vbatts/go-mtree"
 )
 
+var Version string
+
 func main() {
 	app := cli.NewApp()
-	app.Name = mtree.AppName
+	app.Name = "gomtree"
+	app.Version = Version
 	app.Usage = "map a directory hierarchy"
 	app.Description = `The gomtree utility compares the file hierarchy rooted in
 the current directory against a specification read from file or standard input.
@@ -26,7 +29,6 @@ hierarchy or the specification.
 
 This tool is written in likeness to the BSD MTREE(6), with notable additions
 to support xattrs and interacting with tar archives.`
-	app.Version = mtree.Version
 	// cli docs --> https://github.com/urfave/cli/blob/master/docs/v2/manual.md
 	app.Flags = []cli.Flag{
 		// Flags common with mtree(8)

version.go

@@ -1,23 +0,0 @@
-package mtree
-
-import "fmt"
-
-const (
-	// AppName is the name ... of this library/application
-	AppName = "gomtree"
-)
-
-const (
-	// VersionMajor is for an API incompatible changes
-	VersionMajor = 0
-	// VersionMinor is for functionality in a backwards-compatible manner
-	VersionMinor = 5
-	// VersionPatch is for backwards-compatible bug fixes
-	VersionPatch = 1
-
-	// VersionDev indicates development branch. Releases will be empty string.
-	VersionDev = "-dev"
-)
-
-// Version is the specification version that the package types support.
-var Version = fmt.Sprintf("%d.%d.%d%s", VersionMajor, VersionMinor, VersionPatch, VersionDev)