show the date of the latest rate update on the monitor page

fixes #17

apps/monitor/views.py

@@ -1,5 +1,7 @@
 from django.shortcuts import render, redirect
 from django.contrib.auth.decorators import login_required
+from django.conf import settings
+import pytz
 from apps.transactions.models import Transaction
 from apps.rates.models import ExchangeRate
 from apps.monitor.calc import Calc
@@ -13,14 +15,23 @@ def monitor(request):
     total_investment = 0
     current_value = 0
     total_tax_free = 0
+    last_updated = None
     calc = Calc()
 
     for crypto in crypto_currencies:
-        (total_investment, current_value, total_tax_free, rateEUR, rateUSD, out2) = calc.GetCurrentValue(request.user.id, crypto, total_investment, current_value, total_tax_free)
+        (total_investment, current_value, total_tax_free, rateEUR, rateUSD, last_updated, out2) = calc.GetCurrentValue(request.user.id, crypto, total_investment, current_value, total_tax_free)
 
         cryptos.append({"crypto": crypto, "rateEUR": rateEUR, "rateUSD": rateUSD, **out2})
 
-    return render(request,"monitor.html",{'cryptos':cryptos, 'total_tax_free': total_tax_free, 'total_investment': total_investment, 'current_value': current_value})
+    django_timezone = pytz.timezone(settings.TIME_ZONE)
+
+    return render(request,"monitor.html",
+            {'cryptos':cryptos,
+                'total_tax_free': total_tax_free,
+                'total_investment': total_investment,
+                'current_value': current_value,
+                'last_updated': last_updated,
+                'django_timezone': django_timezone})
 
 @login_required
 def graph(request):