update config for Travis CI

remove PHP 5.5 + HHVM, add PHP 7.[123]; add test matrix; add support scripts for CI in composer.json

.travis.yml

@@ -1,10 +1,46 @@
 language: php
 
+cache:
+  directories:
+    - vendor
+    - $HOME/.composer/cache
+
+env:
+  matrix:
+    - DEPENDENCIES=latest
+    - DEPENDENCIES=oldest
+
+install:
+  - >
+    echo;
+    if [ "$DEPENDENCIES" = "latest" ]; then
+      echo "Installing the latest dependencies";
+      composer update --with-dependencies
+    else
+      echo "Installing the lowest dependencies";
+      composer update --with-dependencies --prefer-lowest
+    fi;
+    composer show;
+
 php:
-  - 5.5
   - 5.6
   - 7.0
-  - hhvm
+  - 7.1
+  - 7.2
+  - 7.3
 
-install:
-  - travis_retry composer install --no-interaction
+script:
+  - >
+    echo;
+    echo "Validating the composer.json";
+    composer validate --no-check-all --no-check-lock --strict;
+
+  - >
+    echo;
+    echo "Linting all PHP files";
+    composer ci:lint;
+
+  - >
+    echo;
+    echo "Running the PHPUnit tests";
+    composer ci:tests;

composer.json

@@ -20,5 +20,19 @@
         "psr-0" : {
             "Iamstuartwilson\\" : "src/"
         }
+    },
+    "scripts": {
+        "ci:lint": "find config src tests -name '*.php' -print0 | xargs -0 -n 1 -P 4 php -l",
+        "ci:tests": "./vendor/bin/phpunit tests/",
+        "ci:static": [
+            "@ci:lint"
+        ],
+        "ci:dynamic": [
+            "@ci:tests"
+        ],
+        "ci": [
+            "@ci:static",
+            "@ci:dynamic"
+        ]
     }
 }