Merge pull request #7 from fujiwara/token-env

Read GitHub token from environemnt variable when it is not set in config.

Author: mackee

config.go

@@ -3,6 +3,7 @@ package main
 import (
 	"io"
 	"io/ioutil"
+	"os"
 	"strings"
 
 	"github.com/kayac/go-config"
@@ -52,5 +53,9 @@ func NewConfig(r io.Reader) (Config, error) {
 		return c, errors.Wrap(err, "cannot unmarshal config")
 	}
 
+	if c.Token == "" {
+		c.Token = os.Getenv("GITHUB_TOKEN")
+	}
+
 	return c, nil
 }