DEV: Prefer `create!` over `create` when not checking return value.

db/fixtures/600_themes.rb

@@ -7,13 +7,15 @@ if !Theme.exists?
   dark_scheme ||= ColorScheme.create_from_base(name: name, via_wizard: true, base_scheme_id: "Dark")
 
   name = I18n.t('color_schemes.dark_theme_name')
-  _dark_theme = Theme.create(name: name, user_id: -1,
+
+  _dark_theme = Theme.create!(
+    name: name, user_id: -1,
     color_scheme_id: dark_scheme.id,
-                             user_selectable: true)
+    user_selectable: true
+  )
 
   name = I18n.t('color_schemes.default_theme_name')
-  default_theme = Theme.create(name: name, user_id: -1,
-                               user_selectable: true)
+  default_theme = Theme.create!(name: name, user_id: -1, user_selectable: true)
 
   default_theme.set_default!
 end

lib/wizard/builder.rb

@@ -167,7 +167,12 @@ class Wizard
           theme = themes.find(&:default?)
           theme ||= themes.first
 
-          theme ||= Theme.create(name: name, user_id: @wizard.user.id, color_scheme_id: scheme.id)
+          theme ||= Theme.create!(
+            name: name,
+            user_id: @wizard.user.id,
+            color_scheme_id: scheme.id
+          )
+
           theme.set_default!
         end
       end