Re-implement authentication (#136)

* Remove hasura and hasura-auth

* Implement authentication

server/src/auth/guards/jwt.auth.guard.ts

@@ -0,0 +1,5 @@
+import { Injectable } from '@nestjs/common';
+import { AuthGuard } from '@nestjs/passport';
+
+@Injectable()
+export class JwtAuthGuard extends AuthGuard('jwt') {}