allow blacklist overrides

Author: guybedford

src/transpiler.js

@@ -65,8 +65,9 @@
     options.filename = load.address;
     options.code = true;
     options.ast = false;
-    options.blacklist = options.blacklist || [];
-    options.blacklist.push('react');
+    
+    if (!options.blacklist)
+      options.blacklist = ['react'];
 
     var source = babel.transform(load.source, options).code;