connection.py: Add check to catch defined but empty .session attribute before closing session

README.md: Fix typo

Author: kwollaston

O365/connection.py

@@ -857,8 +857,8 @@ def __del__(self):
         There is no guarantee that this method will be called by the garbage collection
         But this is not an issue because this connections will be automatically closed.
         """
-        if hasattr(self, 'session'):
-            self.session.close()
+        if hasattr(self, 'session') and self.session is not None:
+                self.session.close()
 
 
 def oauth_authentication_flow(client_id, client_secret, scopes=None,

README.md

@@ -21,7 +21,7 @@ The project is currently developed and maintained by [Janscas](https://github.co
 **We are always open to new pull requests!**
 
 #### Rebuilding HTML Docs
-- Install `shpinx` python library
+- Install `sphinx` python library
 
     `pip install sphinx==2.2.2`