init: execute `gitlab:satellites:create` rake task before starting gitlab
init: start unicorn and sidekiq using supervisord
init: do not execute `gitlab:check` rake task

In the forthcoming commit all daemons will be auto started using
supervisord and the execution of the init script will end at the launch
of supervisord. This does not allow room for the `gitlab:check` task to
be executed in such a way that its output.

User's will need to login to the container and manually start the
`gitlab:check` task if the wish to check the status.
init: autostart all daemons when supervisord is started
Merge branch 'launch-via-supervisord'

Refer #149
install: define HOME variable in sidekiq's envivonment
init: clean up
readme: update internal mysql migration instructions
changelog: updated
readme: fix TOC indentation levels
install: switch back to the bash shell for git user
init: configure sidekiq concurrency using the `-c` flag
init: set default SIDEKIQ_CONCURRENCY to 25
Merge branch 'fix-sidekiq-concurrency'

Fixes #174
readme: use simpler mysql GRANT query
init: removed unused sidekiq.yml config template
init: automatically compile assets if relative_url is changed

Closes #171
install: use GITLAB_INSTALL_DIR macro in supervisor configs
readme: added "Contributing" section
readme: fix database server connection error message