Scope sqlite3 patch and apply for Django

Previously the patch was global which caused the django tests to fail if
the sqlite3 tests weren't also run.

Author: ipmb

tests/ext/django/test_middleware.py

@@ -6,6 +6,7 @@
 from aws_xray_sdk.core import xray_recorder, lambda_launcher
 from aws_xray_sdk.core.context import Context
 from aws_xray_sdk.core.models import http, facade_segment, segment
+from aws_xray_sdk.core import patch
 from tests.util import get_new_stubbed_recorder
 import os
 
@@ -66,6 +67,7 @@ def test_fault(self):
         assert exception.type == 'KeyError'
 
     def test_db(self):
+        patch(('sqlite3',))
         url = reverse('call_db')
         self.client.get(url)
         segment = xray_recorder.emitter.pop()

tests/ext/sqlite3/test_sqlite3.py

@@ -6,8 +6,11 @@
 from aws_xray_sdk.core import xray_recorder
 from aws_xray_sdk.core.context import Context
 
-patch(('sqlite3',))
-db = sqlite3.connect(":memory:")
+
+@pytest.fixture(scope="module")
+def db():
+    patch(('sqlite3',))
+    return sqlite3.connect(":memory:")
 
 
 @pytest.fixture(autouse=True)
@@ -24,7 +27,8 @@ def construct_ctx():
     xray_recorder.clear_trace_entities()
 
 
-def test_execute():
+def test_execute(db):
+
     q = 'SELECT name FROM sqlite_master'
     db.execute(q)
 
@@ -35,7 +39,8 @@ def test_execute():
     assert sql['database_version']
 
 
-def test_invalid_syntax():
+def test_invalid_syntax(db):
+    db = sqlite3.connect(":memory:")
     q = 'some_query'
     try:
         db.execute(q)