appveyor.yml in did_you_mean-1.6.3 vs appveyor.yml in did_you_mean-2.0.0

@@ -18,8 +18,9 @@
 before_test:
   - ruby -v
   - gem -v
   - bundle -v
   - gem uni did_you_mean
+  - gem i test-unit-ruby-core
 
 test_script:
   - rake