🔧 PHPCS: don't ignore warnings, don't list scanned files

The `-n` flag will ignore warnings completely, while often it is useful to see them and to fix them.

Using `--runtime-set ignore_warnings_on_exit 1` in the Travis script instead, warnings will be shown, both when a developer runs PHPCS on their own machine, as well as in Travis, but warnings will not cause a failed Travis build.

The `-v` flag will list each file being scanned. This is intended for debugging purposes and not needed for normal use.

.travis.yml

@@ -84,7 +84,7 @@ script:
     # @link https://pear.php.net/package/PHP_CodeSniffer/
     # Uses a custom ruleset based on WordPress. This ruleset is automatically
     # picked up by PHPCS as it's named `phpcs.xml(.dist)`.
-    - if [[ "$SNIFF" == "1" ]]; then $PHPCS_DIR/bin/phpcs; fi
+    - if [[ "$SNIFF" == "1" ]]; then $PHPCS_DIR/bin/phpcs --runtime-set ignore_warnings_on_exit 1; fi
 
 # Receive notifications for build results.
 # @link https://docs.travis-ci.com/user/notifications/#Email-notifications

phpcs.xml.dist

@@ -19,10 +19,8 @@
 	<!-- Pass some flags to PHPCS:
 		 p flag: Show progress of the run.
 		 s flag: Show sniff codes in all reports.
-		 v flag: Print verbose output.
-		 n flag: Do not print warnings.
 	-->
-	<arg value="psvn"/>
+	<arg value="ps"/>
 
 	<!-- Only check the PHP, CSS and SCSS files. JS files are checked separately with JSCS and JSHint. -->
 	<arg name="extensions" value="php,css,scss/css"/>