Admin: New Tutorial

[mikedao]

When I visit '/admin/tutorials/new'
And I fill in 'title' with a meaningful name
And I fill in 'description' with a some content
And I fill in 'thumbnail' with a valid YouTube thumbnail
And I click on 'Save'
Then I should be on '/tutorials/{NEW_TUTORIAL_ID}'
And I should see a flash message that says "Successfully created tutorial."

• Sad path accounted for