go.mod: add go 1.12 line

Without the line go.mod will be changed by the go command.
ulikunitz · Feb 24, 2020 · 818631a · 818631a
1 parent 7dfc1fc
commit 818631a
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/go.mod b/go.mod
@@ -1 +1,3 @@
 module github.com/ulikunitz/xz
+
+go 1.12