Merge pull request rails#45537 from fatkodima/clear-memcache-in-tests

Clear cache in MemCacheStore tests

Author: yahonda

activesupport/test/cache/stores/mem_cache_store_test.rb

@@ -59,6 +59,10 @@ def setup
     @cache.logger = ActiveSupport::Logger.new(File::NULL)
   end
 
+  def teardown
+    @cache.clear
+  end
+
   def after_teardown
     return unless defined?(@_stores) # because skipped test