Delete vendored code and update CI to Go 1.13 (#158)

As the Go community transitions to using the modules ecosystem,
we want to only support one way of managing dependencies.
So this change moves to only using Go modules for dependency management.

This means that our effective minimum Go version increases to Go 1.11.
To account for this, we also update:
  - the documentation
  - Makefile
  - CI scripts

1 files changed, 0 insertions, 17 deletions

diff --git a/vendor/golang.org/x/sys/unix/dirent.go b/vendor/golang.org/x/sys/unix/dirent.go
deleted file mode 100644
index 4407c50..0000000
--- a/vendor/golang.org/x/sys/unix/dirent.go
+++ /dev/null
@@ -1,17 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build aix darwin dragonfly freebsd linux nacl netbsd openbsd solaris
-
-package unix
-
-import "syscall"
-
-// ParseDirent parses up to max directory entries in buf,
-// appending the names to names. It returns the number of
-// bytes consumed from buf, the number of entries added
-// to names, and the new names slice.
-func ParseDirent(buf []byte, max int, names []string) (consumed int, count int, newnames []string) {
-	return syscall.ParseDirent(buf, max, names)
-}