Notable changes

• Twitter:
  • Support ISO 8601 formatted created_at timestamps, which the archive download uses, as well as RFC 2822 from the API.
  • create() and preview_create(): support RSVPs. Tweet them as normal tweets with the RSVP content. (snarfed/bridgy#818)
  • create() and preview_create(): support alt text for images, via AS1 displayName. (snarfed/bridgy#756).
• Instagram:
  • Add global rate limiting lock for scraping. If a scraping HTTP request gets a 429 or 503 response, we refuse to make more requests for 5m, and instead short circuit and return the same error. This can be overridden with a new ignore_rate_limit kwarg to get_activities().
• GitHub:
  • Add tag support to create/preview_create to add label(s) to existing issues (snarfed/bridgy#811).
  • Escape HTML characters (<, >, and &) in content in create() and preview_create() (snarfed/bridgy#810).
  • get_activities() and get_comment() now return ValueError instead of AssertionError on malformed activity_id and comment_id args, respectively.
  • get_activities() bug fix for issues/PRs with no body text.
  • Switch from GraphQL to REST API for creating comments and reactions, since GraphQL hits authorization errors on many org repos. (snarfed/bridgy#824)
  • Improve GraphQL support for comments and users.
• Atom:
  • Shorten and ellipsize feed title when necessary (#144).
• microformats2:
  • Upgrade mf2py to improve a few things like implied p-name detection and whitespace handling (#142, fixes #145, snarfed/bridgy#756, snarfed/bridgy#828).
  • Support alt attribute in <img> tags (snarfed/bridgy#756).