Adding http to server to serve saved CEX orders

[rsercano]

Hi @erkarl,

This's a draft PR to add http functionality into arby as per #85. But in general I'm having problems with rxjs and http. And I'm taking my words back that I said "it's not a big deal to add http after save". It's the biggest deal holy ...

Issues:

• This starts the server but I never get what I wanted from http://localhost:10000/orders, when I do a GET it stucks, even I defined routes in the pipe.
• This never closes the server/db. I also have a problem there.

This branch is over #125. So either you can check this after we merge #125 or you can check both, and your help would be appreciated srsly.

Thanks!