Fix acceptance tests to match recent changes

Descriptions and failure messages of all matchers have been updated, so
fix acceptance tests that reference either of these things.

spec/acceptance/multiple_libraries_integration_spec.rb

@@ -43,9 +43,11 @@ describe 'shoulda-matchers integrates with multiple libraries' do
     it 'allows the use of matchers from both libraries' do
       result = run_rspec_suite
       expect(result).to have_output('2 examples, 0 failures')
-      expect(result).to have_output('should require name to be set')
       expect(result).to have_output(
-        'should require case sensitive unique value for name'
+        'should validate that :name cannot be empty/falsy'
+      )
+      expect(result).to have_output(
+        'should validate that :name is case-sensitively unique'
       )
     end
   end

spec/acceptance/rails_integration_spec.rb

@@ -124,7 +124,9 @@ describe 'shoulda-matchers integrates with Rails' do
     result = run_n_unit_test_suite
 
     expect(result).to indicate_that_tests_were_run(unit: 1, functional: 1)
-    expect(result).to have_output('User should require name to be set')
+    expect(result).to have_output(
+      'User should validate that :name cannot be empty/falsy'
+    )
     expect(result).to have_output('should respond with 200')
   end
 
@@ -146,7 +148,9 @@ describe 'shoulda-matchers integrates with Rails' do
     result = run_rspec_suite
 
     expect(result).to have_output('2 examples, 0 failures')
-    expect(result).to have_output('should require name to be set')
+    expect(result).to have_output(
+      'should validate that :name cannot be empty/falsy'
+    )
     expect(result).to have_output('should respond with 200')
   end
 end