Update gitlab_shell.rb

using instance_variable_defined to avoid @user_tried
Add optional repo path, remove reference to gitolite repo, fixes #77
Replace build in home folder with environment

You can't ever assume that user's home is /home/$USERNAME or /home/git

Preferable is to assume that user running gitlab-shell has repositories in his home (get from the environment).
added support for redis password
GitlabUpdate: use stripped path for repo_name
Use a default for gitlab_url that usually works
Mention Unicorn on a domain socket as an exception
Improve coverage.
Use simplecov for development.
Merge branch 'working_gitlab_url' into 'master'

Use a default for gitlab_url that usually works

This default lets gitlab-shell connect to Unicorn directly, instead of
going through Nginx. This has the following benefits:

- the majority of users no longer has to edit the `gitlab_url`;
- avoid issues when the external GitLab web address does not resolve on
  the GitLab server itself;
- avoid SSL certificate issues.

See merge request !32
Merge pull request #158 from Aigeruth/improvement/coverage

Improve coverage.
Merge branch 'master' of github.com:gitlabhq/gitlab-shell
Merge pull request #155 from ssandler/master

GitlabUpdate: use stripped path for repo_name
Merge pull request #159 from Aigeruth/improvement/simplecov

Use simplecov for development.
Fix tests
Update CHANGELOG

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Fix spec for GitlabConfig.gitlab_url.
Adding support+tests for annotated tags.
Hopefully fixing broken CI build by setting user.name and user.email on the temporary repo.
Need to set config for user.name and user.email before creating the annotated tag.