Fix I18n 1.1 compatibility issues in specs

spec/integration/active_record_compatibility_spec.rb

@@ -77,11 +77,6 @@
   describe "fallbacks" do
     let!(:post) { FallbackPost.create(title: "foo title") }
 
-    it "falls through to default locale with no options" do
-      Mobility.locale = :ja
-      expect(post.title).to eq("foo title")
-    end
-
     it "does not fall through to default locale when fallback: false option passed in" do
       Mobility.locale = :ja
       expect(post.title(fallback: false)).to eq(nil)

spec/mobility/plugins/fallbacks_spec.rb

@@ -73,10 +73,19 @@ def read(locale, **options)
     context "fallbacks is true" do
       let(:fallbacks) { true }
 
+      # @note I18n changed its behavior in 1.1 (see: https://github.com/svenfuchs/i18n/pull/415)
+      #   To correctly test all versions, we actually generate fallbacks and
+      #   determine what the value should be, then check that it matches the
+      #   actual fallback value.
+      # TODO: Simplify this when support for I18n < 1.1 is dropped.
       it "uses default fallbacks" do
         original_default_locale = I18n.default_locale
         I18n.default_locale = :ja
-        expect(subject.read(:"en-US")).to eq("フー")
+        fallbacks = Mobility::Fallbacks.build({})
+        locales = fallbacks[:"en-US"]
+        # in I18n 1.1 value is nil here
+        value = locales.map { |locale| subject.read(locale, locale: true) }.compact.first
+        expect(subject.read(:"en-US")).to eq(value)
         I18n.default_locale = original_default_locale
       end
     end