- Remove port 80 & 443 unused by the container
- Add port 3000 used by gogs application

- `start.sh` will now verify that the port is not already used by another service
- Resolve #1807
- Log when a service is created, or could not be created
- Keep track of which port is already used, including goes & sshd port

- Volumed subfolder now created up in the ENTRYPOINT script, this way
  they are created before S6 even starts making VOLUME.
- The subfolder will be created during VOLUME creation too as ENTRYPOINT
  script will be run before /bin/true
- SSH Keys will now be created on a single key basis not replying on the
  existence of /data/ssh folder

- Fix s6 fifodir error on container restart
- Add .tags* to .gitignore (Atom auto ctags generation)

- Now using a setup script before starting the app. The separation of
the run script and the setup script will make service initialisation a
little bit clearer
- Now calling start.sh script as ENTRYPOINT and S6 as CMD. This way
when running the container with just a shell script, the start.sh
script will be launched before, making debugging easier
- Added note about `.dockerignore` ignored during Docker Hub Automated
Build

- VOLUME for ‘/data’
- Usage of S6 as PID 1 Process
- Usage of ‘socat’ so linked container (like databases) are binded to
localhost
- OpenSSH, Socat Link and Gogs are supervised using S6
- Size of container reduced to ~75Mo