Restructure codebase and update to ES6

[yousufhassan]

Summary:

• Created a router and moved the authentication routes from app.ts to routes/auth.ts
• Added a tsconfig.json for the backend server (don't know how it didn't exist previously)
  • This resulted in several errors, mainly type checking, and for the time being I hacked them by making all types any
  • Will need to go and do better type checking next