Add AUTHORS file

AUTHORS.txt

@@ -0,0 +1,2 @@
+Kevin Burke <kev@inburke.com>
+Sergey Lukjanov <me@slukjanov.name>

Makefile

@@ -1,5 +1,6 @@
 BUMP_VERSION := $(GOPATH)/bin/bump_version
 MEGACHECK := $(GOPATH)/bin/megacheck
+WRITE_MAILMAP := $(GOPATH)/bin/write_mailmap
 
 IGNORES := 'github.com/kevinburke/ssh_config/config.go:U1000 github.com/kevinburke/ssh_config/config.go:S1002 github.com/kevinburke/ssh_config/token.go:U1000'
 
@@ -19,3 +20,10 @@ $(BUMP_VERSION):
 
 release: $(BUMP_VERSION)
 	$(BUMP_VERSION) minor config.go
+
+force: ;
+
+AUTHORS.txt: force | $(WRITE_MAILMAP)
+	$(WRITE_MAILMAP) > AUTHORS.txt
+
+authors: AUTHORS.txt