removed fstrings

HISTORY.rst

@@ -58,3 +58,5 @@ Version 0.4.3:
 Updated tweetmanager dependency to current version (1.1.5)
 Version 0.4.4:
 Fixed another requirement error
+Version 0.4.5:
+Changed f-strings to traditional strings for reasons of compatibility

setup.py

@@ -51,6 +51,6 @@ setup(
     test_suite='tests',
     tests_require=test_requirements,
     url='https://github.com/Serbaf/tweet_model',
-    version='0.4.4',
+    version='0.4.5',
     zip_safe=False,
 )

tweet_model/tweet_model.py

@@ -425,7 +425,7 @@ def get_tweets_from_csv(csv_file):
         for component in field_components:
             error_string += component
             if (checking_dict is None) or (component not in checking_dict):
-                logger.error(f'The field in the header "{error_string}" ' +
+                logger.error('The field in the header ' + error_string +
                              'is not a valid element of a Tweet')
                 raise NotValidTweetError("Header contains field which doesn't"
                                          + " belong to tweet specification: "