feat: Introduce backend test suite with ava

packages/backend/src/graphql/queries/get-user.test.ts

@@ -0,0 +1,8 @@
+import test from 'ava';
+
+const fn = () => 'foo';
+
+test('getUser graphQL query', (t) => {
+  // TODO: Write a test for getUser graphQL query
+  t.is(fn(), 'foo');
+});