language: ruby
dist: trusty
sudo: false
before_script:
  - bundle update
cache: bundler
rvm:
  - 1.9.3-p551
  - 2.0.0-p648
  - 2.1.10
  - 2.2.7
  - 2.3.4
  - 2.4.1
  - ruby-head
  - jruby-1.7.26
  - jruby-9.1.12.0
  - jruby-head
  - rbx-3.84
matrix:
  allow_failures:
    - rvm: ruby-head
    - rvm: jruby-head

language: ruby
dist: trusty
sudo: false
before_install:
  - gem update bundler
before_script:
  - bundle update
cache: bundler
rvm:
  - 1.9.3-p551
  - 2.0.0-p648
  - 2.1.10
  - 2.2.7
  - 2.3.4
  - 2.4.1
  - ruby-head
  - jruby-1.7.26
  - jruby-9.1.12.0
  - jruby-head
  - rbx-3.84
matrix:
  allow_failures:
    - rvm: ruby-head
    - rvm: jruby-head

Update bundler before installing gems.
Update bundler before installing gems.

Ruby 1.9.3-p551 on Travis CI includes an ancient version of bundler
(v1.7.6) that is not compatible with new versions of RubyGems. This
causes an 'undefined method `spec' for nil:NilClass' error (see
https://travis-ci.org/tzinfo/tzinfo/jobs/272252812).
