Use gofumpt to format code

gofumpt (mvdan.cc/gofumpt) is a fork of gofmt with stricter rules.

Brought to you by

	git ls-files \*.go | grep -v ^vendor/ | xargs gofumpt -s -w

Looking at the diff, all these changes make sense.

Also, replace gofmt with gofumpt in golangci.yml.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

rlimit_linux.go

@@ -1,7 +1,10 @@
 package main
 
-import "fmt"
-import "golang.org/x/sys/unix"
+import (
+	"fmt"
+
+	"golang.org/x/sys/unix"
+)
 
 var rlimitMap = map[string]int{
 	"RLIMIT_CPU":        unix.RLIMIT_CPU,