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, 29 deletions

diff --git a/vendor/golang.org/x/sys/unix/dev_openbsd.go b/vendor/golang.org/x/sys/unix/dev_openbsd.go
deleted file mode 100644
index f3430c4..0000000
--- a/vendor/golang.org/x/sys/unix/dev_openbsd.go
+++ /dev/null
@@ -1,29 +0,0 @@
-// Copyright 2017 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.
-
-// Functions to access/create device major and minor numbers matching the
-// encoding used in OpenBSD's sys/types.h header.
-
-package unix
-
-// Major returns the major component of an OpenBSD device number.
-func Major(dev uint64) uint32 {
-	return uint32((dev & 0x0000ff00) >> 8)
-}
-
-// Minor returns the minor component of an OpenBSD device number.
-func Minor(dev uint64) uint32 {
-	minor := uint32((dev & 0x000000ff) >> 0)
-	minor |= uint32((dev & 0xffff0000) >> 8)
-	return minor
-}
-
-// Mkdev returns an OpenBSD device number generated from the given major and minor
-// components.
-func Mkdev(major, minor uint32) uint64 {
-	dev := (uint64(major) << 8) & 0x0000ff00
-	dev |= (uint64(minor) << 8) & 0xffff0000
-	dev |= (uint64(minor) << 0) & 0x000000ff
-	return dev
-}