composer: require phpstan/phpstan-shim instead of phpstan/phpstan

Author: JanTvrdik

composer.json

@@ -11,7 +11,7 @@
 		"consistence/coding-standard": "^2.0.0",
 		"jakub-onderka/php-parallel-lint": "^0.9.2",
 		"phing/phing": "^2.16.0",
-		"phpstan/phpstan": "^0.9",
+		"phpstan/phpstan-shim": "^0.9.2",
 		"phpunit/phpunit": "^6.3",
 		"slevomat/coding-standard": "^3.3.0"
 	},