Fix copy-pasta

The description for --head said it was the head branch instead of head branch.
2016-04-21 12:15:07 +02:00 · 2016-04-21 12:15:07 +02:00 · 9413795ec7
--- a/commands/pull_request.go
+++ b/commands/pull_request.go
@ -43,7 +43,7 @@ pull-request -i <ISSUE>
 		(usually "master").

 	-h, --head <HEAD>
-		The base branch in "[OWNER:]BRANCH" format. Defaults to the current branch.
+		The head branch in "[OWNER:]BRANCH" format. Defaults to the current branch.

 	-a, --assign <USER>
 		Assign GitHub <USER> to this pull request.