Remove "save as draft"

Removes the creating status completely as well as the abandoned cards system. It will
always resume drafts if they exist, for a given collection and user.

https://app.box-car.com/5986089/cards/2489

test/controllers/cards_controller_test.rb

@@ -15,11 +15,23 @@ class CardsControllerTest < ActionDispatch::IntegrationTest
     assert_response :success
   end
 
-  test "create" do
+  test "create a new draft" do
     assert_difference -> { Card.count }, 1 do
       post collection_cards_path(collections(:writebook))
     end
-    assert_redirected_to card_path(Card.last)
+
+    assert Card.last.drafted?
+    assert_redirected_to Card.last
+  end
+
+  test "create resumes existing draft if it exists" do
+    draft = collections(:writebook).cards.create!(creator: users(:kevin), status: :drafted)
+
+    assert_no_difference -> { Card.count } do
+      post collection_cards_path(collections(:writebook))
+    end
+
+    assert_redirected_to draft
   end
 
   test "show" do