Update nginx-golang-mysql dockercompose (#141)

* Add missing expose field to docker compose files (#124)

Signed-off-by: javi <javier@okteto.com>
Signed-off-by: Alvaro Carpio <alvanxp@outlook.com>

* add MySql healthcheck to dependency for backend

Signed-off-by: Alvaro Carpio <alvanxp@outlook.com>

Co-authored-by: Javier López Barba <j.lopezbarb@gmail.com>