azure-functions: Add missing test configuration files. (#2312)

These missing configurations, which weren't identified in the original
implementation of `apollo-server-azure-functions` in #1926, are responsible
for the failures which have surfaced in the #2228, which updates Jest to v24.x.

packages/apollo-server-azure-functions/jest.config.js

@@ -0,0 +1,3 @@
+const config = require('../../jest.config.base');
+
+module.exports = Object.assign(Object.create(null), config);

packages/apollo-server-azure-functions/src/__tests__/tsconfig.json

@@ -0,0 +1,8 @@
+{
+  "extends": "../../../../tsconfig.test.base",
+  "include": ["**/*"],
+  "references": [
+    { "path": "../../" },
+    { "path": "../../../apollo-server-integration-testsuite" },
+  ]
+}