Introduce pyupgrade

Closes #1742 (closed)

Introducing pyupgrade.

Again, I've made one commit per rule.

arkindex/project/tests/__init__.py

@@ -67,7 +67,7 @@ class _AssertExactQueriesContext(CaptureQueriesContext):
         if not self.path.exists():
             try:
                 self.path.write_text(actual_sql)
-            except IOError as e:
+            except OSError as e:
                 raise AssertionError(
                     f"Could not assert on SQL queries; the file at {self.path} did not exist. "
                     "A new file could not be created with the current SQL queries."