cleanup/small refactor + first tests

Backend/endpoints/time.go

@@ -34,16 +34,16 @@ func TimeHandler(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
-func parseTimestamp(r *http.Request, get_key string, fallback string) (time.Time, error) {
-	_timestamp_get := r.URL.Query().Get(get_key)
-	if _timestamp_get == "" {
-		_timestamp_get = fallback
+func parseTimestamp(r *http.Request, getKey string, fallback string) (time.Time, error) {
+	getTimestamp := r.URL.Query().Get(getKey)
+	if getTimestamp == "" {
+		getTimestamp = fallback
 	}
-	timestamp_get, err := time.Parse("2006-01-02", _timestamp_get)
+	Timestamp, err := time.Parse("2006-01-02", getTimestamp)
 	if err != nil {
 		return time.Now(), err
 	}
-	return timestamp_get, nil
+	return Timestamp, nil
 }
 
 // Returns bookings from DB with similar card uid -> checks for card uid in http query params