Remove Ruby versions from Travis CI config with ended maintenance
Remove Ruby versions from Travis CI config with ended maintenance

[1.9.3](https://www.ruby-lang.org/en/news/2015/02/23/support-for-ruby-1-9-3-has-ended/)
[2.0.0](https://www.ruby-lang.org/en/news/2016/02/24/support-plan-of-ruby-2-0-0-and-2-1/)

thomasfl/filewatcher