refactor #157 Add support for PHP 7.3 & remove fake Symfony builds (pamil)

This PR was merged into the 1.3 branch.

Discussion
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Requiring dev Symfony packages still keeps others on the highest possible version.

Commits
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02793dd Add support for PHP 7.3 & remove fake Symfony builds

Author: pamil

.travis.yml

@@ -6,6 +6,7 @@ sudo: false
 
 php:
     - 7.2
+    - 7.3
 
 cache:
     yarn: true
@@ -17,9 +18,6 @@ env:
     global:
         - SYLIUS_CACHE_DIR=$HOME/.sylius-cache
         - SYLIUS_BUILD_DIR=etc/build
-    matrix:
-        - SYMFONY_VERSION="3.4.*"
-        - SYMFONY_VERSION="4.2.*"
 
 before_install:
     - phpenv config-rm xdebug.ini
@@ -31,12 +29,6 @@ before_install:
     - set -a && source tests/Application/.env.test && set +a
 
 install:
-    - composer require "symfony/browser-kit:${SYMFONY_VERSION}" --no-interaction --no-update
-    - composer require "symfony/debug-bundle:${SYMFONY_VERSION}" --no-interaction --no-update
-    - composer require "symfony/dotenv:${SYMFONY_VERSION}" --no-interaction --no-update
-    - composer require "symfony/intl:${SYMFONY_VERSION}" --no-interaction --no-update
-    - composer require "symfony/web-profiler-bundle:${SYMFONY_VERSION}" --no-interaction --no-update
-    - composer require "symfony/web-server-bundle:${SYMFONY_VERSION}" --no-interaction --no-update
     - composer install --no-interaction --prefer-dist
     - (cd tests/Application && yarn install)