remove "_ex" from celery test
rename "fetch_tenhou_log" -> "fetch_tenhou_log_string"
  this func now return string
  this func now get request url from configs
add config "tenhou_log_url"
rename "FetchLogError" -> "FetchError"
  add doc
rename "rsp" -> "response"
add fetch_tenhou_records
add core.models
  + GameLogAndPlayer
  + GameRecords