Revert standardizing Travis config

Author: schlessera

.travis.yml

@@ -1,11 +1,8 @@
-os: linux
-dist: xenial
+sudo: false
+dist: trusty
 
 language: php
-php: 7.4
-
-services:
-  - mysql
+php: 7.2
 
 notifications:
   email:
@@ -26,6 +23,7 @@ env:
     - WP_CLI_BIN_DIR="$TRAVIS_BUILD_DIR/vendor/bin"
 
 before_install:
+  - export XMLLINT_INDENT="	"
   - |
     # Remove Xdebug for a huge performance increase:
     if [ -f ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/xdebug.ini ]; then
@@ -48,12 +46,17 @@ script:
 
 jobs:
   include:
-    - stage: test
-      php: 7.4
-      env: WP_VERSION=latest
-    - stage: test
-      php: 7.3
-      env: WP_VERSION=latest
+    - stage: sniff
+      addons:
+        apt:
+          packages:
+            - libxml2-utils
+      script:
+        - composer lint
+        - xmllint --noout --schema ./vendor/squizlabs/php_codesniffer/phpcs.xsd ./*/ruleset.xml
+        - composer phpcs
+        - diff -B --tabsize=4 ./WP_CLI_CS/ruleset.xml <(xmllint --format "./WP_CLI_CS/ruleset.xml")
+      env: BUILD=sniff
     - stage: test
       php: 7.2
       env: WP_VERSION=latest
@@ -69,7 +72,10 @@ jobs:
     - stage: test
       php: 5.6
       env: WP_VERSION=3.7.11
-      dist: trusty
     - stage: test
       php: 5.6
       env: WP_VERSION=trunk
+    - stage: test
+      php: 5.4
+      dist: precise
+      env: WP_VERSION=5.1