Feature/logging

[leihuayi]

• rename "cd" folder to "infra"
• filebeat docker image + conf file (needs env var "OVH_TOKEN" specified)
• write logs to backend/logs folder locally using python logging+ gelf-formatter libraries
• route http://localhost:5000/logs or http://preprod.basegun.fr/api/logs to show logs in browser (blocked in prod)
• write the following informations in logs:

• date and time of identification request (timestamp)
• url of uploaded file (string)
• result label (string)
• result confidence score (float in 0-100)
• processing time of ML algorithm (float in secs)
• uploading time of photo (float in secs)
• approximative geolocation of user (string of "latitude, longitude")
• unique identification of user (sha-256 hash of ip+user-agent+hardwareConcurrency in frontend)
• (TODO) result judged correct or not by user