Revert "Install codesniffer"

This reverts commit 545e309d4b.

composer.json

@@ -42,10 +42,9 @@
     "zendframework/zend-diactoros": "1.4.1"
   },
   "require-dev": {
-    "ext-pdo": "*",
     "phpunit/dbunit": "^2.0",
     "phpunit/phpunit": "^4.0",
-    "squizlabs/php_codesniffer": "3.4.2"
+    "ext-pdo": "*"
   },
   "autoload": {
     "psr-4": {

composer.lock

@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "c1b6812ceff4ba052c142547de9d209a",
+    "content-hash": "4e7d1fa77dfae365ac340e54ddd9ae6c",
     "packages": [
         {
             "name": "doctrine/annotations",
@@ -3021,57 +3021,6 @@
             "homepage": "https://github.com/sebastianbergmann/version",
             "time": "2015-06-21T13:59:46+00:00"
         },
-        {
-            "name": "squizlabs/php_codesniffer",
-            "version": "3.4.2",
-            "source": {
-                "type": "git",
-                "url": "https://github.com/squizlabs/PHP_CodeSniffer.git",
-                "reference": "b8a7362af1cc1aadb5bd36c3defc4dda2cf5f0a8"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/squizlabs/PHP_CodeSniffer/zipball/b8a7362af1cc1aadb5bd36c3defc4dda2cf5f0a8",
-                "reference": "b8a7362af1cc1aadb5bd36c3defc4dda2cf5f0a8",
-                "shasum": ""
-            },
-            "require": {
-                "ext-simplexml": "*",
-                "ext-tokenizer": "*",
-                "ext-xmlwriter": "*",
-                "php": ">=5.4.0"
-            },
-            "require-dev": {
-                "phpunit/phpunit": "^4.0 || ^5.0 || ^6.0 || ^7.0"
-            },
-            "bin": [
-                "bin/phpcs",
-                "bin/phpcbf"
-            ],
-            "type": "library",
-            "extra": {
-                "branch-alias": {
-                    "dev-master": "3.x-dev"
-                }
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "BSD-3-Clause"
-            ],
-            "authors": [
-                {
-                    "name": "Greg Sherwood",
-                    "role": "lead"
-                }
-            ],
-            "description": "PHP_CodeSniffer tokenizes PHP, JavaScript and CSS files and detects violations of a defined set of coding standards.",
-            "homepage": "https://github.com/squizlabs/PHP_CodeSniffer",
-            "keywords": [
-                "phpcs",
-                "standards"
-            ],
-            "time": "2019-04-10T23:49:02+00:00"
-        },
         {
             "name": "symfony/yaml",
             "version": "v3.4.24",