Include *.test.js files in test run (#171)

When working on something else, I noticed that `.test.js` files were not
running due to `jest.config.json` not including them. I went ahead and
re-enabled these tests to make sure that unit tests are actually being
run.

jest.config.json

@@ -2,7 +2,6 @@
   "setupFiles": ["./jest.setup.js"],
   "testPathIgnorePatterns": ["dist", "/node_modules/", "/build/"],
   "roots": ["<rootDir>"],
-  "testMatch": ["<rootDir>/**/*.spec.js"],
   "moduleFileExtensions": ["ts", "js", "json"],
   "testEnvironment": "node",
   "collectCoverage": true,

upcoming-release-notes/171.md

@@ -0,0 +1,6 @@
+---
+category: Maintenance
+authors: [Jackenmen]
+---
+
+Fix app-sync.test.js not being ran due to faulty jest configuration