* Bump API Version to v5.2
* InputInvoiceMessageContent & simplify *Markup.__eq__ on the fly
* Updates to send_invoice
* InlineQuery updatees and new parameter for InlineQueryhandler
* VCScheduled - not integrated into Message yet
* Bump requirements-dev.txt versions
* Message.voice_chat_scheduled & new Filters.status_update.vcs
* Some doc updates
* Review
* All praise harshil, the god of finding typos :)
* Review
* More warnings
