Fix flake8 errors

Author: LadyChristina

data_collection_scripts/collect_block_data.py

@@ -41,7 +41,7 @@ def collect_data(ledgers, from_block, to_date):
             logging.info(f'Done querying {ledger}')
         except Exception as e:
             if 'Quota exceeded' in repr(e):
-                logging.info(f'Quota exceeded for this service account key. Aborting..')
+                logging.info('Quota exceeded for this service account key. Aborting..')
                 break
             else:
                 logging.info(f'{ledger} query failed, please make sure it is properly defined.')

tests/test_aggregate.py

@@ -4,7 +4,7 @@
 import pytest
 from consensus_decentralization.helper import INTERIM_DIR
 from consensus_decentralization.aggregate import aggregate, Aggregator, divide_timeframe
-from consensus_decentralization.helper import get_clustering_flag, get_aggregated_data_dir_name
+from consensus_decentralization.helper import get_clustering_flag
 
 
 @pytest.fixture