Changes gems to use https path rather than git path. Git path does not
work behind some firewalls and/or proxies.

Use latest gitlab-grit fork to prevent gollum override gitlab-grit. Fixes issues related to gpg signed commits and other fixes from gitlab/grit fork

This commit replaces the old database backed Wiki system with the
excellent Gollum git based Wiki system.

The UI has been updated to allow for utilizing the extra features
that Gollum provides. Specifically:

* Edit page now allows you to choose the content format.
* Edit page allows you to provide a commit message for the change.
* History page now shows Format, Commit Message, and Commit Hash.
* A new Git Access page has been added with the Wiki Repo URL.
* The default page has been changed to Home from Index to match
the Gollum standard.

The old Wiki model has been left in tact to provide for the
development of a migration script that will move all content stored
in the old Wiki system into new Gollum Wikis.

Updating this dependency fixed my Ruby 2.0 installation issues.

add grape-entity, that is split from grape 0.3.0.
remove usage of deprecated error_format, that is removed in grape 0.2.3.