Upgrade typeshed, fixes #1084

jedi/third_party/README_typeshed.md

@@ -12,3 +12,19 @@ https://github.com/davidhalter/typeshed.git for two reasons:
 
 - Jedi doesn't understand Tuple.__init__ properly.
 - Typeshed has a bug: https://github.com/python/typeshed/issues/2999
+
+Therefore we need a bit of a complicated process to upgrade typeshed:
+
+    cd jedi/third_party/typeshed
+    git remote add upstream https://github.com/python/typeshed
+    git fetch upstream
+    git checkout jedi
+    git rebase upstream/master
+    git push -f
+
+    git push
+    cd ../../..
+    git commit jedi/third_party/typeshed -m "Upgrade typeshed"
+
+If merge conflicts appear, just make sure that only one commit from Jedi
+appears.

test/completion/stdlib.py

@@ -190,6 +190,10 @@ def huhu(db):
     #? sqlite3.Connection()
     db
 
+with sqlite3.connect() as c:
+    #? sqlite3.Connection()
+    c
+
 # -----------------
 # hashlib
 # -----------------