Bug 1539667 [wpt PR 16086] - Remove the build_css_testsuite job, a=testonly

Automatic update from web-platform-tests
Remove the build_css_testsuite job

This is no longer required. It's also the final job that uses travis
for anything.

--

wpt-commits: 87f87e1276cdbf9f4af14dcb12d3d7bc1200d7c5
wpt-pr: 16086

testing/web-platform/tests/.travis.yml

@@ -1,36 +0,0 @@
-dist: trusty
-sudo: required
-language: python
-branches:
-  only:
-    - master
-before_install:
-  # This needs be sourced as it sets various env vars
-  - . ./tools/ci/before_install.sh
-install:
-  - ./tools/ci/install.sh
-matrix:
-  # The use of `if` conditionals to exclude jobs from master should align with
-  # jobs unconditionally listed by `./wpt test-jobs`, regardless of affected
-  # paths. (The reverse is not true, as the manifest job could run on PRs too.)
-  fast_finish: true
-  include:
-    - name: "build-css-testsuites.sh"
-      if: type = pull_request
-      os: linux
-      python: "2.7"
-      env: JOB=build_css SCRIPT=css/build-css-testsuites.sh
-  exclude:
-    - env:  # exclude empty env from the top-level above
-  allow_failures:
-    - env: JOB=build_css SCRIPT=css/build-css-testsuites.sh
-script:
-  - ./tools/ci/run.sh
-cache:
-  directories:
-    - $HOME/.cache/pip
-    - $HOME/meta
-notifications:
-  email:
-    on_success: never
-    on_failure: always