v2.4.0

Features

• add 'py.typed' declaration (#919) (c993504)
• add api key support (#826) (3b15092)

Bug Fixes

• deps: allow cachetools 5.0 for python 3.7+ (#937) (1eae37d)
• fix the message format for metadata server exception (#916) (e756f08)

Documentation

• fix intersphinx link for 'requests-oauthlib' (#921) (967be4f)
• note ValueError in verify_oauth2_token (#928) (82bc5f0)