Add support for repositories hosted on GitLab

[raphaelstolt]

To also support users opting for GitLab, it would be useful to aid them in constructing a package structure targeted for GitLab. This could be done by introducing a --profile or similar named option which excepts gitlab or github as a value, with github being the default.

Templates for GitLab
Examples:

• https://gitlab.com/gitlab-org/gitlab-ce/tree/master/.gitlab/issue_templates
• https://gitlab.com/gitlab-org/gitlab-ce/tree/master/.gitlab/merge_request_templates

Also related - .gitlab-ci.yml #207