Fix makefile

Add missing dependencies, and make sure cs-fix works

Makefile

@@ -1,23 +1,29 @@
 .PHONY: check
 check: lint cs tests phpstan
 
+vendor:
+	composer install
+
+build-cs/vendor:
+	composer install --working-dir build-cs
+
 .PHONY: tests
-tests:
+tests: vendor
 	php vendor/bin/phpunit
 
 .PHONY: lint
-lint:
+lint: vendor
 	php vendor/bin/parallel-lint --colors --show-deprecated \
 		src tests
 
 .PHONY: cs
-cs:
-	composer install --working-dir build-cs && php build-cs/vendor/bin/phpcs
+cs: build-cs/vendor
+	php build-cs/vendor/bin/phpcs
 
 .PHONY: cs-fix
-cs-fix:
-	vendor/bin/phpcbf
+cs-fix: build-cs/vendor
+	build-cs/vendor/bin/phpcbf
 
 .PHONY: phpstan
-phpstan:
+phpstan: vendor
 	php vendor/bin/phpstan analyse -l 9 -c phpstan.neon src tests