fix(CI): actually run credo

SpaceEEC · SpaceEEC · commit 8dc095d6d9bb · 2019-04-02T18:17:45.000+02:00
diff --git a/.travis.yml b/.travis.yml
@@ -7,6 +7,7 @@ matrix:
       otp_release: '21.0.8'
       script:
         - mix format --check-formatted
+        - mix credo --strict
         - mix test
 
     - language: elixir
