WIP|FEATURE: Test on multiple php versions

* Use different jobs to run in parallel.
* Use different docker image for each php version.
* Provide common way to install composer on each image.

.gitlab-ci.yml

@@ -1,18 +1,25 @@
-image: 'composer:latest'
-
 before_script:
-  - apk add --no-cache make
   - >
-    composer install
-    --optimize-autoloader
-    --no-interaction
-    --no-ansi
+    apt-get update
+    && apt-get install -y
+    make
+    wget
+    --no-install-recommends
+    && rm -r /var/lib/apt/lists/*
+  - make install-composer
   - make install
 
 stages:
   - test
 
-test:functional:
+test:5.6:
+  image: php:5.6
+  stage: test
+  script:
+    - ./vendor/bin/phpunit
+
+test:7.0:
+  image: php:7.0
   stage: test
   script:
     - ./vendor/bin/phpunit

Makefile

@@ -4,7 +4,7 @@ DEFAULT_STANDARD = Typo3Update
 CUSTOM_STANDARDS = $(abspath ./src/Standards/)
 
 install:
-	composer install
+	composer install --optimize-autoloader --no-interaction --no-ansi
 	$(BIN_PHPCS) --config-set installed_paths $(CUSTOM_STANDARDS)
 	$(BIN_PHPCS) -i | grep Typo3Update
 	$(BIN_PHPCS) --config-set default_standard $(DEFAULT_STANDARD)
@@ -14,3 +14,12 @@ test-search:
 	$(BIN_PHPCS) -p --colors -s PROJECT_PATH
 test-fix:
 	$(BIN_PHPCBF) -p --colors -s PROJECT_PATH
+
+# For CI:
+install-composer:
+	wget https://composer.github.io/installer.sig -O - -q | tr -d '\n' > installer.sig
+	php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
+	php -r "if (hash_file('SHA384', 'composer-setup.php') === file_get_contents('installer.sig')) { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"
+	php composer-setup.php
+	php -r "unlink('composer-setup.php'); unlink('installer.sig');"
+	php composer.phar install