Build/Test tools: Trim the test matrix on Travis in order to speed up the 4.7 branch build.

This removes the PHP 7.0, 5.5, 5.4, 5.3, and nightly jobs.

Fixes #41707


git-svn-id: https://develop.svn.wordpress.org/branches/4.7@41307 602fd350-edb4-49c9-b593-d223f7449a82

.travis.yml

@@ -15,20 +15,12 @@ matrix:
   - php: 7.1
     env: WP_TRAVISCI=travis:js
   - php: 7.1
-  - php: 7.0
   - php: 5.6
   - php: 5.6
     env: WP_TRAVIS_OBJECT_CACHE=true
     services: memcached
-  - php: 5.5
-  - php: 5.4
-  - php: 5.3
-    dist: precise
   - php: 5.2
     dist: precise
-  - php: nightly
-  allow_failures:
-  - php: nightly
 before_install:
 - |
   if [[ "$WP_TRAVISCI" == "travis:phpunit" ]]; then