Changed the campaign email address
Revert "Take new campaign form down"

This reverts commit d9a5d1dec889d0af499d0d8601fbd888da7b1911.

Conflicts:
	app/views/layouts/_header.html.slim
Ability to archive influencers

In the influencer's page, it's possible to mark it as archived.
When it's done, the influencer's page won't be accessed by common users, only
admins.
Update gems and force newer ruby version.
Rollback the ability to create campaigns and fix specs due to Gem's update.
Fix conflicts and merge pull request #41
Fix gemfile.lock