remove go.mod in go.mod

Signed-off-by: Guillaume J. Charmes <guillaume@charmes.net>
diff --git a/go.mod b/go.mod
deleted file mode 100644
index f73bcd6..0000000
--- a/go.mod
+++ /dev/null
@@ -1,3 +0,0 @@
-module github.com/kr/pty
-
-go 1.12