Rails run all tests except one

I want to run all my unit tests on my ruby on rails project except one. This is because i have pdf generation tests that don't work when ran by travic CI. So on travis I want to run all tests except the pdf generation tests. Is there any check i can do? Is there a way to check if the application is running locally or on travis CI? Both are test environments. Here is my travis.yml

language: ruby
rvm:
- '2.1.5'
script:
- 'bundle exec rake'
- 'bundle exec rubocop'
- 'bundle exec rails_best_practices'