language: ruby
cache: bundler
rvm:
  - 2.5
  - 2.6
  - 2.7
script: bundle exec rake test
env:
  - REPORTER=default

language: ruby
cache: bundler
rvm:
  - 2.6
  - 2.7
  - 3.0
script: bundle exec rake test
env:
  - REPORTER=default

Add Ruby 3.0 to continuous integration build
Add Ruby 3.0 to continuous integration build

This commit removes Ruby 2.5.x from the Travis build. This isn't because
I know it no longer works, but because I've decided to aim to support
the three most recent releases of Ruby.

Version 2.5 probably still works (though I haven't tested it with the
libraries that are updated in this commit).
