Improve the fuel and fuelcost type handling

influx_frontend.py

@@ -25,7 +25,11 @@ def add_time():
     odometer = request.form['odometer']
     oilhealth= request.form['oilhealth']
     fuel = request.form['fuel']
+    if fuel != '':
+        fuel = float(fuel)
     fuelcost = request.form['fuelcost']
+    if fuelcost != '':
+        fuelcost = float(fuelcost)
     winter = request.form['winter']
 
     json_body = [