Remove the Sauce Travis jobs

Sauce cannot be kept working beyond April 17, see
#9903.

Given that they are not very reliable and take up Travis capacity, and
that we don't have a replacement for this that can be put in place
before April 17, it seems best to turn it off right away.

The code is left in place until this is determined to work.

.travis.yml

@@ -19,9 +19,6 @@ before_install:
   - . ./tools/ci/before_install.sh
 install:
   - ./tools/ci/install.sh
-env:  # required at the top-level for allow_failures to work below
-  global:
-    - SAUCE_USERNAME=w3c-ttwf
 matrix:
   fast_finish: true
   include:
@@ -65,16 +62,6 @@ matrix:
       env:
         - secure: "YTSXPwI0DyCA1GhYrLT9KMEV6b7QQKuEeaQgeFDP38OTzJ1+cIj3CC4SRNqbnJ/6SJwPGcdqSxLuV8m4e5HFFnyCcQnJe6h8EMsTehZ7W3j/fP9UYrJqYqvGpe3Vj3xblO5pwBYmq7sg3jAmmuCgAgOW6VGf7cRMucrsmFeo7VM="
         - JOB=stability SCRIPT=tools/ci/ci_stability.sh PRODUCT=chrome:dev
-    - os: linux
-      python: "2.7"
-      env:
-        - secure: "YTSXPwI0DyCA1GhYrLT9KMEV6b7QQKuEeaQgeFDP38OTzJ1+cIj3CC4SRNqbnJ/6SJwPGcdqSxLuV8m4e5HFFnyCcQnJe6h8EMsTehZ7W3j/fP9UYrJqYqvGpe3Vj3xblO5pwBYmq7sg3jAmmuCgAgOW6VGf7cRMucrsmFeo7VM="
-        - JOB=stability SCRIPT=tools/ci/ci_stability.sh PRODUCT=sauce:safari:11.0 PLATFORM='macOS 10.12'
-    - os: linux
-      python: "2.7"
-      env:
-        - secure: "YTSXPwI0DyCA1GhYrLT9KMEV6b7QQKuEeaQgeFDP38OTzJ1+cIj3CC4SRNqbnJ/6SJwPGcdqSxLuV8m4e5HFFnyCcQnJe6h8EMsTehZ7W3j/fP9UYrJqYqvGpe3Vj3xblO5pwBYmq7sg3jAmmuCgAgOW6VGf7cRMucrsmFeo7VM="
-        - JOB=stability SCRIPT=tools/ci/ci_stability.sh PRODUCT=sauce:MicrosoftEdge:16.16299 PLATFORM='Windows 10'
     - python: 2.7
       env: JOB=tools_unittest TOXENV=py27 HYPOTHESIS_PROFILE=ci SCRIPT=tools/ci/ci_tools_unittest.sh
     - python: 3.6
@@ -105,12 +92,6 @@ matrix:
     - env:
         - secure: "YTSXPwI0DyCA1GhYrLT9KMEV6b7QQKuEeaQgeFDP38OTzJ1+cIj3CC4SRNqbnJ/6SJwPGcdqSxLuV8m4e5HFFnyCcQnJe6h8EMsTehZ7W3j/fP9UYrJqYqvGpe3Vj3xblO5pwBYmq7sg3jAmmuCgAgOW6VGf7cRMucrsmFeo7VM="
         - JOB=stability SCRIPT=tools/ci/ci_stability.sh PRODUCT=chrome:dev
-    - env:
-        - secure: "YTSXPwI0DyCA1GhYrLT9KMEV6b7QQKuEeaQgeFDP38OTzJ1+cIj3CC4SRNqbnJ/6SJwPGcdqSxLuV8m4e5HFFnyCcQnJe6h8EMsTehZ7W3j/fP9UYrJqYqvGpe3Vj3xblO5pwBYmq7sg3jAmmuCgAgOW6VGf7cRMucrsmFeo7VM="
-        - JOB=stability SCRIPT=tools/ci/ci_stability.sh PRODUCT=sauce:MicrosoftEdge:16.16299 PLATFORM='Windows 10'
-    - env:
-        - secure: "YTSXPwI0DyCA1GhYrLT9KMEV6b7QQKuEeaQgeFDP38OTzJ1+cIj3CC4SRNqbnJ/6SJwPGcdqSxLuV8m4e5HFFnyCcQnJe6h8EMsTehZ7W3j/fP9UYrJqYqvGpe3Vj3xblO5pwBYmq7sg3jAmmuCgAgOW6VGf7cRMucrsmFeo7VM="
-        - JOB=stability SCRIPT=tools/ci/ci_stability.sh PRODUCT=sauce:safari:11.0 PLATFORM='macOS 10.12'
 script:
   - ./tools/ci/run.sh
 cache: