Fix lru_cache/memoized decorator for Python 3.7

Author: amotl

grafana_client/api.py

@@ -76,7 +76,7 @@ def connect(self):
         return grafana_info
 
     @property
-    @memoized
+    @memoized(maxsize=1)
     def version(self):
         grafana_info = self.health.check()
         version = grafana_info["version"]