Added missing slots to context managers (#763)

* Add missing slot to context managers

* Bump version and fix CHANGES

Author: Pliner

Diff for: CHANGES.txt

@@ -1,3 +1,9 @@
+1.1.0b2 (2020-12-09)
+^^^^^^^^^^^^^^^^^^^^
+
+* Added missing slots to context managers `#763 <https://github.com/aio-libs/aiopg/pull/763>`_
+
+
 1.1.0b1 (2020-12-07)
 ^^^^^^^^^^^^^^^^^^^^
 

Diff for: aiopg/__init__.py

@@ -21,7 +21,7 @@
            'Connection', 'Cursor', 'Pool', 'version', 'version_info',
            'DEFAULT_TIMEOUT', 'IsolationLevel', 'Transaction')
 
-__version__ = '1.1.0b1'
+__version__ = '1.1.0b2'
 
 version = __version__ + ' , Python ' + sys.version
 

Diff for: aiopg/utils.py

@@ -100,6 +100,8 @@ async def __aexit__(self, exc_type, exc, tb):
 
 
 class _SAConnectionContextManager(_ContextManager):
+    __slots__ = ()
+
     def __aiter__(self):
         return self
 
@@ -108,21 +110,25 @@ async def __anext__(self):
             self._obj = await self._coro
 
         try:
-            return (await self._obj.__anext__())
+            return await self._obj.__anext__()
         except StopAsyncIteration:
             self._obj.close()
             self._obj = None
             raise
 
 
 class _PoolContextManager(_ContextManager):
+    __slots__ = ()
+
     async def __aexit__(self, exc_type, exc, tb):
         self._obj.close()
         await self._obj.wait_closed()
         self._obj = None
 
 
 class _TransactionPointContextManager(_ContextManager):
+    __slots__ = ()
+
     async def __aexit__(self, exc_type, exc_val, exc_tb):
         if exc_type is not None:
             await self._obj.rollback_savepoint()
@@ -133,6 +139,8 @@ async def __aexit__(self, exc_type, exc_val, exc_tb):
 
 
 class _TransactionBeginContextManager(_ContextManager):
+    __slots__ = ()
+
     async def __aexit__(self, exc_type, exc_val, exc_tb):
         if exc_type is not None:
             await self._obj.rollback()
@@ -143,6 +151,8 @@ async def __aexit__(self, exc_type, exc_val, exc_tb):
 
 
 class _TransactionContextManager(_ContextManager):
+    __slots__ = ()
+
     async def __aexit__(self, exc_type, exc, tb):
         if exc_type:
             await self._obj.rollback()