Revert "Attempt to test multiple laravel versions with travis"

This reverts commit 1ae02c3.

.travis.yml

@@ -9,28 +9,6 @@ cache:
   directories:
     - $HOME/.composer/cache
 
-env:
-  - ILLUMINATE_VERSION=5.3.*
-  - TESTBENCH_VERSION=3.3.*
-
-matrix:
-  include:
-    - php: 5.6
-      env: ILLUMINATE_VERSION=5.3.*
-    - php: 5.6
-      env: ILLUMINATE_VERSION=5.4.* TESTBENCH_VERSION=3.4.*
-    - php: 7.0
-      env: ILLUMINATE_VERSION=5.3.*
-    - php: 7.0
-      env: ILLUMINATE_VERSION=5.4.* TESTBENCH_VERSION=3.4.*
-    - php: 7.1
-      env: ILLUMINATE_VERSION=5.3.*
-    - php: 7.1
-      env: ILLUMINATE_VERSION=5.4.* TESTBENCH_VERSION=3.4.*
-
 before_script:
-  - composer require "illuminate/support:${ILLUMINATE_VERSION}" --no-update
-  - composer require "illuminate/database:${ILLUMINATE_VERSION}" --no-update
-  - composer require "orchestra/testbench:${TESTBENCH_VERSION}" --dev --no-update
-  - composer update ${COMPOSER_FLAGS} --no-interaction --prefer-dist
-  - composer dumpautoload -o
+  - travis_retry composer update ${COMPOSER_FLAGS} --no-interaction --prefer-dist
+  - composer dumpautoload -o