Support multiple attachments (#29)

* Support multiple attachments
* Support single attachment syntax in addition to multiple
* Re-add import Goland removed while optimizing imports for me.

main.go

@@ -79,6 +79,11 @@ func main() {
 			Usage:  "attachment filename",
 			EnvVar: "PLUGIN_ATTACHMENT",
 		},
+		cli.StringSliceFlag{
+			Name:   "attachments",
+			Usage:  "attachment filename(s)",
+			EnvVar: "PLUGIN_ATTACHMENTS",
+		},
 
 		// Drone environment
 		// Repo
@@ -375,6 +380,7 @@ func run(c *cli.Context) error {
 			Subject:        c.String("template.subject"),
 			Body:           c.String("template.body"),
 			Attachment:     c.String("attachment"),
+			Attachments:    c.StringSlice("attachments"),
 		},
 	}
 

plugin.go

@@ -89,6 +89,7 @@ type (
 		Subject        string
 		Body           string
 		Attachment     string
+		Attachments    []string
 	}
 
 	Plugin struct {
@@ -203,6 +204,10 @@ func (p Plugin) Exec() error {
 			message.Attach(p.Config.Attachment)
 		}
 
+		for _, attachment := range p.Config.Attachments {
+			message.Attach(attachment)
+		}
+
 		if err := gomail.Send(closer, message); err != nil {
 			log.Errorf("Could not send email to %q: %v", recipient, err)
 			return err