fix: properly handle directory replacement

The previous version _also_ deleted the temp working dir, causing issues with subsequent directory access.

plugins/builder/functions.go

@@ -0,0 +1,20 @@
+package builder
+
+import (
+	"io/ioutil"
+	"os"
+	"path"
+)
+
+func removeAllContents(basePath string) error {
+	dir, err := ioutil.ReadDir(basePath)
+	if err != nil {
+		return err
+	}
+
+	for _, d := range dir {
+		os.RemoveAll(path.Join([]string{basePath, d.Name()}...))
+	}
+
+	return nil
+}