update code to reflect the new minimum python version 3.7

- update string format method
- remove redundant default arguments from function  calls
- remove unused imports
- remove unicode identifier from strings, it's default in py3 (see: https://stackoverflow.com/a/4182635/12201331)

allianceauth/eveonline/tests/__init__.py

@@ -18,7 +18,7 @@ def set_logger(logger_name: str, name: str) -> object:
         '%(asctime)s - %(levelname)s - %(module)s:%(funcName)s - %(message)s'
     )
     f_handler = logging.FileHandler(
-        '{}.log'.format(os.path.splitext(name)[0]),
+        f'{os.path.splitext(name)[0]}.log',
         'w+'
     )
     f_handler.setFormatter(f_format)