Update BuildCommand.php

Fixed condition for check of force option.
Previously if we put anything as force option it converted to true, which skipped building. While the expected behaviour was to create new build.

src/Command/BuildCommand.php

@@ -96,7 +96,7 @@ protected function buildTarget(AssetTarget $build, Factory $factory, Arguments $
         $compiler = $factory->compiler();
 
         $name = $writer->buildFileName($build);
-        if ($writer->isFresh($build) && $args->getOption('force')) {
+        if ($writer->isFresh($build) && $args->getOption('force') === false) {
             $io->out('<info>Skip building</info> ' . $name . ' existing file is still fresh.');
 
             return;