lvis builder can't be created

[IRDonch]

Short description Attempting to create the builder for the lvis dataset fails with an exception.

Environment information

• Operating System: Ubuntu 18.04

• Python version: 3.6.9

• tensorflow-datasets/tfds-nightly version: tensorflow-datasets 4.4.0

• tensorflow/tf-nightly version: tensorflow 2.6.2

• Does the issue still exists with the last tfds-nightly package (pip install --upgrade tfds-nightly) ? Yes

Reproduction instructions

import tensorflow_datasets as tfds
tfds.builder("lvis")

Link to logs https://gist.github.com/IRDonch/28230e78c4b6f97a53afd936b62f8635

Expected behavior The builder should be created successfully.

Additional context It's likely broken because lvis_classes.txt is not listed in setup.py, so it doesn't get included in the wheel.

[maxzuo]

This seems to be resolved in some of the latest nightly builds. @IRDonch can you give it a look?