Make travis work again.

.travis.yml

@@ -1,13 +1,32 @@
 language: php
+
 php:
-    - "5.4"
-    - "5.5"
-    - "5.6"
+  - 5.3
+  - 5.4
+  - 5.5
+  - 5.6
+
+env:
+  - CONTAO_VERSION=~3.2.0
+  - CONTAO_VERSION=~3.3.0
+  - CONTAO_VERSION=~3.4.0
+  - CONTAO_VERSION=~3.5.0
+
+# Exclude impossible Contao Version combinations.
+matrix:
+  exclude:
+    - php: 5.3
+      env: CONTAO_VERSION=~3.5.0
 
 sudo: false
 
 install:
-    - composer install --prefer-dist --dev
+  - travis_retry composer self-update && composer --version
+  - travis_retry composer require contao/core $CONTAO_VERSION --no-update
+  - travis_retry composer update --prefer-dist --no-interaction
 
-script:
-    - ant -keep-going
+script: ant -keep-going
+
+# Hack to make things work again - we can not use a shallow repository.
+git:
+  depth: 2147483647