Add howto to readme and convert roadmap into limitations

More information in readme.

Init script is already checked out and does not need to be downloaded ag...

In order to use GitLab ACL - we fetch projects via API
Then we filter projects with CI enabled and show them first
It reduce page load since we do network request.
But we dont need to keep and sync any access lists

Fix Build#duration when TimeZone is not UTC

Change gravatar_icon helper to handle ssl

Better support for ansi colors and text styles

This commit refactors the gravatar_icon helper method to handle ssl.
This is because when running gitlab-ci with ssl enabled, it gives a
warning because portions of the page are not secure. In addition to
refactoring this method, it also adds some configuration values to the
application.yml.example file that are needed for the gravatar_icon
helper method. It also adds default values for settings relating to
gitlab_ci and gravatar. This is because the values will need defaults
if they aren't specified in the application.yml. It also adds the
no_avatar.png since it is being used in the gravatar_icon helper
method. Finally, this commit adds spec tests to cover the
refactored method.

adds support for
- background color (16 and 256 color tables)
- normal and bright color (16 color table)
- bold text
- italic text
- underlined text
- crossed-out text
- concealed text

Add display name to runner model