Move gh check to the Haskell binary

app/SlackBuilder/CommandLine.hs

@@ -16,7 +16,7 @@ import Options.Applicative
     , info
     , fullDesc
     , subparser
-    , command
+    , command, optional
     )
 
 data SlackBuilderCommand
@@ -32,6 +32,7 @@ data PackagistArguments = PackagistArguments
 data GhArguments = GhArguments
     { owner :: Text
     , name :: Text
+    , transform :: Maybe Text
     } deriving (Eq, Show)
 
 newtype TextArguments = TextArguments Text
@@ -48,6 +49,7 @@ ghArguments :: Parser GhArguments
 ghArguments = GhArguments
     <$> argument str (metavar "OWNER")
     <*> argument str (metavar "NAME")
+    <*> optional (argument str (metavar "TRANSFORM"))
 
 slackBuilderParser :: ParserInfo SlackBuilderCommand
 slackBuilderParser = info slackBuilderCommand fullDesc