feature: add log of all texts received by bot

[GuyHerrmann]

Overview
if something happens and a user messages important information to the bot accidently, this can be seen in the log files when we check them (maybe if someone sends and SOS we would routinely check the log files). Also, if people are struggling with the app we could check the log files at the end of the day and see who is struggling/ sending the wrong information and get hold of them

Implementation
Every time a message is received, it could be appended to a daily log file/ database which could be accesible to the admins in case of emergency before it has been processed.
Or,
it could be added if it is not one of the accebtable messages.
Additional info: time, registered/not registered member, phone number, message

Log file/database could be quieried after or just read through (exported as xls?)
Log files may even be useful for querying to see usage of the app/ how often people are reporting (is that ethical?)

Could be accesible in the admin page view

Questions/Assumptions
Ethical questions on holding pretty sensitive data? Should log files just be deleted each day once checked through?