Add simple write_file() util func

gen/gen_cid/utils.py

@@ -15,6 +15,10 @@ def read_file(path):
         file_content = f.read()
     return file_content
 
+def write_file(path, data):
+    with open(path, "w+") as f:
+        f.write(data)
+
 def write_json(content, outpath):
     # create path if not existing
     out_dir = os.path.dirname(outpath)