fix make

Author: Shibuya Satoshi

HACKING.md

@@ -37,10 +37,3 @@ Install `apigen` before releasing new version.
 1. Edit [GitHub releases](https://github.com/line/line-bot-sdk-php/releases)
 
 That's all. It will be publish on [composer](https://packagist.org/packages/linecorp/line-bot-sdk) automatically.
-
-e.g.
-
-```
-$ make release VERSION=1.2.3
-# Then, edit GitHub releases
-```

Makefile

@@ -19,18 +19,6 @@ copyright:
 
 check: test copyright phpcs phpmd
 
-release:
-ifndef VERSION
-	@tput setaf 1
-	@echo '[ERROR] $$VERSION is missing; it must be specified'
-	@echo 'USAGE:'
-	@echo '    make release VERSION=1.2.3'
-	@tput sgr0
-	@exit 255
-endif
-	git tag $(VERSION)
-	git push origin $(VERSION)
-
 clean:
 	rm -rf vendor composer.lock