Get phaza/laravel-postgis working again? Better travis config

.travis.yml

@@ -8,6 +8,10 @@ addons:
 services:
   - postgresql
 
+env:
+  global:
+    - setup=basic
+
 php:
   - 7.0
   - nightly
@@ -15,12 +19,19 @@ matrix:
   allow_failures:
     - php: nightly
 
+before_install:
+  - phpenv config-rm xdebug.ini
+  - travis_retry composer self-update --preview
+
+install:
+  - if [[ $setup = 'basic' ]];  then travis_retry composer install --no-interaction --prefer-dist; fi
+  - if [[ $setup = 'stable' ]]; then travis_retry composer update --no-interaction --prefer-dist --prefer-stable; fi
+  - if [[ $setup = 'lowest' ]]; then travis_retry composer update --no-interaction --prefer-dist --prefer-lowest --prefer-stable; fi
+
 before_script:
   - psql -U travis -c 'create database travis_ci_test'
   - psql -U travis -d travis_ci_test -c 'create extension postgis'
   - cp .env.travis .env
-  - travis_retry composer self-update --preview
-  - travis_retry composer install --no-interaction
   - php artisan key:generate
   - php artisan migrate
   - php artisan db:seed