Add Go module file

I.A · I.A · commit 54a4530d5148 · 2019-12-23T17:39:13.000+01:00
diff --git a/go.mod b/go.mod
@@ -0,0 +1,3 @@
+module github.com/sinoz/bytecat
+
+go 1.13

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+module github.com/sinoz/bytecat`
	`2`	`+`
	`3`	`+go 1.13`