Merge pull request #829 from cakephp/othercorey-patch-1

Fix plugin-installer dev dependency

Author: othercorey

Diff for: composer.json

@@ -32,6 +32,7 @@
     "require-dev": {
         "cakephp/authorization": "^1.3.2",
         "cakephp/cakephp-codesniffer": "^3.0",
+        "cakephp/plugin-installer": "^1.3",
         "phpunit/phpunit": "^5.7.14|^6.0"
     },
     "autoload": {