.travis.yml in avromatic-0.26.0 vs .travis.yml in avromatic-0.27.0

@@ -8,7 +8,9 @@
 script:
   - bundle exec rubocop
   - bundle exec appraisal rails4_1 rake spec
   - bundle exec appraisal rails4_2 rake spec
   - bundle exec appraisal rails5_0 rake spec
+  - bundle exec appraisal rails5_1 rake spec
   - bundle exec appraisal avro-patches-4_1 rake spec
   - bundle exec appraisal avro-patches-5_0 rake spec
+  - bundle exec appraisal avro-patches-5_1 rake spec