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, 82 deletions

diff --git a/vendor/golang.org/x/sys/unix/timestruct.go b/vendor/golang.org/x/sys/unix/timestruct.go
deleted file mode 100644
index 4a672f5..0000000
--- a/vendor/golang.org/x/sys/unix/timestruct.go
+++ /dev/null
@@ -1,82 +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.
-
-// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
-
-package unix
-
-import "time"
-
-// TimespecToNsec converts a Timespec value into a number of
-// nanoseconds since the Unix epoch.
-func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
-
-// NsecToTimespec takes a number of nanoseconds since the Unix epoch
-// and returns the corresponding Timespec value.
-func NsecToTimespec(nsec int64) Timespec {
-	sec := nsec / 1e9
-	nsec = nsec % 1e9
-	if nsec < 0 {
-		nsec += 1e9
-		sec--
-	}
-	return setTimespec(sec, nsec)
-}
-
-// TimeToTimespec converts t into a Timespec.
-// On some 32-bit systems the range of valid Timespec values are smaller
-// than that of time.Time values.  So if t is out of the valid range of
-// Timespec, it returns a zero Timespec and ERANGE.
-func TimeToTimespec(t time.Time) (Timespec, error) {
-	sec := t.Unix()
-	nsec := int64(t.Nanosecond())
-	ts := setTimespec(sec, nsec)
-
-	// Currently all targets have either int32 or int64 for Timespec.Sec.
-	// If there were a new target with floating point type for it, we have
-	// to consider the rounding error.
-	if int64(ts.Sec) != sec {
-		return Timespec{}, ERANGE
-	}
-	return ts, nil
-}
-
-// TimevalToNsec converts a Timeval value into a number of nanoseconds
-// since the Unix epoch.
-func TimevalToNsec(tv Timeval) int64 { return int64(tv.Sec)*1e9 + int64(tv.Usec)*1e3 }
-
-// NsecToTimeval takes a number of nanoseconds since the Unix epoch
-// and returns the corresponding Timeval value.
-func NsecToTimeval(nsec int64) Timeval {
-	nsec += 999 // round up to microsecond
-	usec := nsec % 1e9 / 1e3
-	sec := nsec / 1e9
-	if usec < 0 {
-		usec += 1e6
-		sec--
-	}
-	return setTimeval(sec, usec)
-}
-
-// Unix returns ts as the number of seconds and nanoseconds elapsed since the
-// Unix epoch.
-func (ts *Timespec) Unix() (sec int64, nsec int64) {
-	return int64(ts.Sec), int64(ts.Nsec)
-}
-
-// Unix returns tv as the number of seconds and nanoseconds elapsed since the
-// Unix epoch.
-func (tv *Timeval) Unix() (sec int64, nsec int64) {
-	return int64(tv.Sec), int64(tv.Usec) * 1000
-}
-
-// Nano returns ts as the number of nanoseconds elapsed since the Unix epoch.
-func (ts *Timespec) Nano() int64 {
-	return int64(ts.Sec)*1e9 + int64(ts.Nsec)
-}
-
-// Nano returns tv as the number of nanoseconds elapsed since the Unix epoch.
-func (tv *Timeval) Nano() int64 {
-	return int64(tv.Sec)*1e9 + int64(tv.Usec)*1000
-}