Add method to linter reset_counters

django_migration_linter/migration_linter.py

@@ -72,11 +72,7 @@ class MigrationLinter(object):
         self.warnings_as_errors = warnings_as_errors
 
         # Initialise counters
-        self.nb_valid = 0
-        self.nb_ignored = 0
-        self.nb_warnings = 0
-        self.nb_erroneous = 0
-        self.nb_total = 0
+        self.reset_counters()
 
         # Initialise cache. Read from old, write to new to prune old entries.
         if self.should_use_cache():
@@ -91,6 +87,13 @@ class MigrationLinter(object):
             connection=connections[self.database], load=True
         )
 
+    def reset_counters(self):
+        self.nb_valid = 0
+        self.nb_ignored = 0
+        self.nb_warnings = 0
+        self.nb_erroneous = 0
+        self.nb_total = 0
+
     def should_use_cache(self):
         return self.django_path and not self.no_cache