Lock on major for PHPCS

see #57

Author: gmazzap

composer.json

@@ -30,7 +30,7 @@
     "minimum-stability": "stable",
     "require": {
         "php": ">=7",
-        "squizlabs/php_codesniffer": "~3.6.0",
+        "squizlabs/php_codesniffer": "^3.6.0",
         "dealerdirect/phpcodesniffer-composer-installer": "~0.7.0",
         "wp-coding-standards/wpcs": "^2.3",
         "automattic/vipwpcs": "^2.2",