Metasploit .travis.yml for all rubies with specs and metasploit-yard's yard task that exits non-zero when there is undocumented code

.travis.yml

env:
  matrix:
    - RAKE_TASK=spec
language: ruby
matrix:
  # documentation coverage is not influenced by ruby implementation, so only run once
  include:
    - rvm: 2.1
      env: RAKE_TASK=yard
rvm:
  - '1.9.3'
  - '2.0'
  - '2.1'
  - 'ruby-head'
  - 'jruby-19mode'
  - 'rbx-2.2'
script: "bundle exec rake $RAKE_TASK"