added helpers to leverage for various libraries

app/helpers/tar_helper.py

@@ -0,0 +1,9 @@
+import io
+import tarfile
+
+def raw_to_tar(raw_object):
+  tarball = io.BytesIO(raw_object)
+  return tarfile.open(fileobj=tarball, mode='r:gz')
+
+def extract_file_from_tar(tar, file_name):
+  return tar.extractfile(tar.getmember(file_name))