ts-node-dev bug demonstration of issue #57

Steps to reproduce:

1. npm install
2. npm run watch-buggy
3. curl http://localhost:11223/request --> prints out "BOOM1"
4. Edit src/app.ts and change BOOM1 to BOOM2, save --> server restarts
5. curl http://localhost:11223/request --> still prints out "BOOM1"
6. Edit src/app.ts and change BOOM2 to BOOM3, save --> server restarts
7. curl http://localhost:11223/request --> now prints out "BOOM3"

When running with npm run watch-works it works correctly.