Adding `Installation from package` instructions on README #92

I added Ubuntu 12 and 14 separated because they have differents `/etc/apt/sources.list.d/azuki.list` contents;

What do you think about the `[sudo]` included at shell commands?

I could not solve the dependencies installation in fedora, but this command "resolves" that issue:
```bash
$ [sudo] yum install docker-io libnss-resolver azk
```