remove fxp-asset, update travis config

.travis.yml

@@ -1,26 +1,42 @@
-dist: trusty
+dist: xenial
 
 sudo: false
 
+group: edge
+
 language: php
 
-php:
-    - '5.4'
-    - '5.5'
-    - '5.6'
-    - '7.0'
-    - '7.1'
+env:
+    global:
+        - COMPOSER_UPDATE="--prefer-dist --no-interaction --no-progress --optimize-autoloader"
+        - COMPOSER_CONFIG="--global github-oauth.github.com b7244dc99194b22416d5ce46d511ce04049b23de"
+
+# cache vendor dirs
+cache:
+    directories:
+        - vendor
+        - $HOME/.composer/cache
+
+matrix:
+    fast_finish: true
+    include:
+        - php: "7.4"
+        - php: "7.3"
+        - php: "7.2"
+        - php: "7.1"
+        - php: "7.0"
+        - php: "5.6"
+        - php: "5.5"
+          dist: trusty
+        - php: "5.4"
+          dist: trusty
 
 install:
-    - composer config --global github-oauth.github.com b7244dc99194b22416d5ce46d511ce04049b23de
-    - composer global require "fxp/composer-asset-plugin:~1.3.1"
-    - composer update --prefer-dist --no-interaction
+    - travis_retry composer self-update
+    - export PATH="$HOME/.composer/vendor/bin:$PATH"
+    - travis_retry composer config $COMPOSER_CONFIG
+    - travis_retry composer update $COMPOSER_UPDATE
 
 script:
     - vendor/bin/codecept run unit --coverage-xml
     - vendor/bin/coveralls
-
-# cache vendor dirs
-cache:
-    directories:
-        - $HOME/.composer/cache

composer.json

@@ -36,17 +36,20 @@
     "codeception/specify": "~0.4.3",
     "satooshi/php-coveralls": "^1.0"
   },
+  "autoload": {
+    "psr-4": {
+      "cetver\\LanguageSelector\\": ""
+    }
+  },
   "config": {
     "fxp-asset": {
-      "installer-paths": {
-        "npm-asset-library": "vendor/npm",
-        "bower-asset-library": "vendor/bower"
-      }
+      "enabled": false
     }
   },
-  "autoload": {
-    "psr-4": {
-      "cetver\\LanguageSelector\\": ""
+  "repositories": [
+    {
+      "type": "composer",
+      "url": "https://asset-packagist.org"
     }
-  }
+  ]
 }