fiery 1.3.0

• Added serve_static() method to Fire to serve a directory of static files
  directly outside the request loop
• Move code over to rlang style programming
• Full rewrite of condition handling.
• Added logger_logger() to use the logger package for logging
• Fire$log() now supports cli syntax in the message
• Support for the reqres_problem conditions
• Fire$log() now supports passing in a condition as message
• Added Fire$data_store field to suppleant Fire$get_data() and friends. It
  provides direct acces to the global data store
• Allow naming plugins when they are attached
• showcase in Fire$ignite()/Fire$run() can now take a string giving the
  path to open the browser at.
• Improve the default session id handling and added session_id_cookie() helper
  function for constructing session ID extractor
• Deprecate use of future. Fire$delay() and Fire$time() now uses quosures
  and Fire$async() has been soft deprecated in favor of letting the user use
  whatever async framework they like
• Support returning promises in request events, and automated error logging
  from promises in all events
• Added websocket-opened event that allows the user to add a handler that
  modifies the WebSocket connection when it is established