Raises if can't find DB file

pyheatpump/db.py

@@ -76,6 +76,9 @@ class DB():
             except sqlite3.IntegrityError as e:
                 print(e)
                 return []
+            except sqlite3.OperationalError as e:
+                raise Exception('Can\'t find DB file %s'.format(filename)) from e
+
 
 
 class RowClass(object):