Add main that reads build info and prints main version

Author: Timothy Yen

go.mod

@@ -0,0 +1,3 @@
+module github.com/kollektiv/examplegotool
+
+go 1.14

main.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"log"
+	"runtime/debug"
+)
+
+func main() {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		log.Fatalln("could not reading build info")
+	}
+
+	log.Println("main module version:", info.Main.Version)
+}