Build/Test Tools: Use 7.3 for PHP 7.3

Travis now supports PHP7.3 without workarounds, so let's remove the workarounds.

Merges [43726] to trunk.

See #44771.


git-svn-id: https://develop.svn.wordpress.org/trunk@43975 602fd350-edb4-49c9-b593-d223f7449a82

.travis.yml

@@ -12,14 +12,7 @@ env:
     - WP_TRAVISCI=travis:phpunit
 matrix:
   include:
-  - php: 7.3.0RC1
-    sudo: required
-    dist: xenial
-    services: mysql
-    addons:
-      apt:
-        packages:
-          - libzip4
+  - php: 7.3
   - php: 7.2
     env: WP_TRAVISCI=travis:format
   - php: 7.1
@@ -41,7 +34,7 @@ matrix:
   - php: nightly
   allow_failures:
   - php: nightly
-  - php: 7.3.0RC1
+  - php: 7.3
 before_install:
 - |
   if [[ "$WP_TRAVISCI" == "travis:phpunit" ]]; then
@@ -75,7 +68,7 @@ before_script:
   # Install the specified version of PHPUnit depending on the PHP version:
   if [[ "$WP_TRAVISCI" == "travis:phpunit" ]]; then
     case "$TRAVIS_PHP_VERSION" in
-      7.3.0RC1|7.2|7.1|7.0|nightly)
+      7.3|7.2|7.1|7.0|nightly)
         echo "Using PHPUnit 6.x"
         travis_retry composer global require "phpunit/phpunit:^6"
         ;;