Unexpected keys apt, elapsed_time and on_pull_requests

[cas--]

Although below config snippet works on Travis, running it through the linter results in:

    in notifications.slack.template section: unknown template variable elapsed_time
    in notifications.slack section: unexpected key on_pull_requests, dropping
    value for addons section is empty, dropping
    in addons section: unexpected key apt, dropping

language: python

addons:
  apt:
    packages:
    - aspell

notifications:
  slack:
    rooms:
      - secure: abc
    on_pull_requests: false
    template:
      - "Build <%{build_url}|#%{build_number}> (<%{compare_url}|%{commit}>) of %{repository}@%{branch} in PR <%{pull_request_url}|#%{pull_request_number}> by %{author} %{result} in %{elapsed_time}"

[ntwb]

I was about to report the addons issue, I'll piggy back this onto this issue here:

The docs at https://docs.travis-ci.com/user/installing-dependencies/#Adding-APT-Packages state:

addons:
  apt:
    packages:
    - cmake
    - time

So the linter or the docs should be updated

[thomaseizinger]

Same thing for the notifications.slack section. The syntax is described here: https://docs.travis-ci.com/user/notifications/#Notifications-of-PR-builds
The link links to the hipchat section but I think the configuration is the same for any channel.