Remove deprecated attributes from Legislation::Draft::Version

Some fields from LegislationDraftVersion are translatable and we no
longer need them. This commit will remove the annoying deprecation
warning thrown by Globalize gem after gem version update.

db/migrate/20190221164559_remove_deprecated_translatable_fields_from_legislation_draft_versions.rb

@@ -0,0 +1,9 @@
+class RemoveDeprecatedTranslatableFieldsFromLegislationDraftVersions < ActiveRecord::Migration[4.2]
+  def change
+    remove_column :legislation_draft_versions, :title, :string
+    remove_column :legislation_draft_versions, :changelog, :text
+    remove_column :legislation_draft_versions, :body, :text
+    remove_column :legislation_draft_versions, :body_html, :text
+    remove_column :legislation_draft_versions, :toc_html, :text
+  end
+end

db/schema.rb

@@ -722,16 +722,11 @@ ActiveRecord::Schema.define(version: 20190607160900) do
 
   create_table "legislation_draft_versions", force: :cascade do |t|
     t.integer  "legislation_process_id"
-    t.string   "title"
-    t.text     "changelog"
     t.string   "status",                 default: "draft"
     t.boolean  "final_version",          default: false
-    t.text     "body"
     t.datetime "hidden_at"
     t.datetime "created_at",                               null: false
     t.datetime "updated_at",                               null: false
-    t.text     "body_html"
-    t.text     "toc_html"
     t.index ["hidden_at"], name: "index_legislation_draft_versions_on_hidden_at", using: :btree
     t.index ["legislation_process_id"], name: "index_legislation_draft_versions_on_legislation_process_id", using: :btree
     t.index ["status"], name: "index_legislation_draft_versions_on_status", using: :btree