Provider Statistics added.

Rates command added with a test.

Updated to include added migration.

app/dao/provider_rates_dao.py

@@ -0,0 +1,9 @@
+from app.models import ProviderRates
+from app import db
+from app.dao.dao_utils import transactional
+
+
+@transactional
+def create_provider_rates(provider, valid_from, rate):
+    provider_rates = ProviderRates(provider=provider, valid_from=valid_from, rate=rate)
+    db.session.add(provider_rates)