Rename the PHPCS ruleset.

If the file is called `phpcs.xml` or `phpcs.xml.dist`, it is automatically picked up by PHPCS.

A `phpcs.xml` is given preference over a `phpcs.xml.dist` file. So renaming the file to `phpcs.xml.dist` allows for people to use the file provided by `_s` if they choose not to add their own, but also leaves people the freedom to easily overrule it.

.travis.yml

@@ -83,9 +83,10 @@ script:
     # -s flag: Show sniff codes in all reports.
     # -v flag: Print verbose output.
     # -n flag: Do not print warnings. (shortcut for --warning-severity=0)
-    # --standard: Use WordPress as the standard.
+    # Uses a custom ruleset based on WordPress. This ruleset is automatically
+    # picked up by PHPCS as it's named `phpcs.xml(.dist)`.
     # --extensions: Only sniff PHP files.
-    - if [[ "$SNIFF" == "1" ]]; then $PHPCS_DIR/scripts/phpcs -p -s -v -n . --standard=./codesniffer.ruleset.xml --extensions=php; fi
+    - if [[ "$SNIFF" == "1" ]]; then $PHPCS_DIR/scripts/phpcs -p -s -v -n . --extensions=php; fi
 
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