get_album: track_number returns none when track unavailable + test #393

	name: Build Documentation

	on:
	push:
	paths:
	- ytmusicapi/**
	- docs/**
	pull_request:
	branches:
	- main
	paths:
	- ytmusicapi/**
	- docs/**

	jobs:
	build:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3
	- name: Set up Python
	uses: actions/setup-python@v3
	with:
	python-version: '3.x'
	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install . sphinx sphinx-rtd-theme
	- name: Build documentation
	run: \|
	cd docs
	make html

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