Improve gitlab_shell spec and replace `system()` with `exec()`

Do not fall on discover deployment keys. Closes #25

Require openssl

Fix the "uninitialized constant GitlabNet::OpenSSL (NameError)"
after upgrading to ruby 2.0

http_settings configuration option added.

Now it supports:

 * self_signed_cert option to allow self-signed certificates over https protocol.
 * user and password options to pass though http auth.

gitlab_net#host: slash is missing

This also randomizes the key_id used in the tests.

We don't need to keep the ruby process around once we've
established that it's ok to run a git command.

* Used mocks to test if methods are colled
* Increased coverage
* Removed duplication and excess verbage

gitlab_update: Stop matching all on .git

Commenting out . to stop all single char matches rather then just ".git"

Master Sync

Fixed install script