Update composer dependencies and Travis.yml

Closes #94

.travis.yml

@@ -1,3 +1,4 @@
+dist: trusty
 language: php
 
 services:
@@ -12,6 +13,10 @@ addons:
     - mysql-client-core-5.6
     - mysql-client-5.6
 
+cache:
+    directories:
+        - $HOME/.composer/cache/files
+
 matrix:
     include:
         - php: 7.1
@@ -35,14 +40,12 @@ branches:
 
 # setup requirements for running db tests
 before_install:
-  - if [ "$TEST_CONFIG" != "" ] ; then ./bin/.travis/prepare_unittest.sh ; fi
+    - ./bin/.travis/prepare_unittest.sh
 
 before_script:
     # Disable memory_limit for composer
     - echo "memory_limit=-1" >> ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/travis.ini
-    - mkdir -p ~/.composer
-    - cp bin/.travis/composer-auth.json ~/.composer/auth.json
-    - composer install --no-progress --no-interaction --prefer-dist
+    - travis_retry composer install --no-progress --no-interaction --prefer-dist
     - if [ "$SOLR_VERSION" != "" ] ; then ./vendor/ezsystems/ezplatform-solr-search-engine/bin/.travis/init_solr.sh ; fi
 
 script:
@@ -51,3 +54,7 @@ script:
 
 notifications:
     email: false
+
+# reduce depth (history) of git checkout
+git:
+    depth: 30

composer.json

@@ -10,15 +10,18 @@
         }
     ],
     "require": {
-        "ezsystems/ezpublish-kernel": "^6.13.6@dev || ^7.2.5@dev",
-        "ezsystems/repository-forms": "^1.9 || ^2.0",
+        "php": "^7.1",
+        "ext-xsl": "*",
+        "ext-dom": "*",
+        "ezsystems/ezpublish-kernel": "^7.5.1@dev",
+        "ezsystems/repository-forms": "^2.5.0",
         "ezsystems/ezplatform-richtext": "^1.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^5.7",
-        "matthiasnoback/symfony-dependency-injection-test": "~1.0",
-        "ezsystems/ezplatform-solr-search-engine": "^1.5",
-        "friendsofphp/php-cs-fixer": "~2.7.1"
+        "phpunit/phpunit": "^5.7.27",
+        "matthiasnoback/symfony-dependency-injection-test": "^1.2.0",
+        "ezsystems/ezplatform-solr-search-engine": "^1.5.7",
+        "friendsofphp/php-cs-fixer": "~2.7.5"
     },
     "autoload": {
         "psr-4": {