Merge pull request #2 from szepeviktor/patch-3

Use Composer-style constrain

Author: Greg Bowler

Dockerfile

@@ -5,7 +5,8 @@ LABEL repository="https://github.com/php-actions/phpstan"
 LABEL homepage="https://github.com/php-actions/phpstan"
 LABEL maintainer="Greg Bowler <greg.bowler@g105b.com>"
 
-RUN composer global require --no-progress phpstan/phpstan 0.12.*
+RUN composer global require --no-progress "phpstan/phpstan:^0.12.0"
 RUN ln -s /tmp/vendor/bin/phpstan /usr/local/bin/phpstan
+
 COPY entrypoint /usr/local/bin/entrypoint
-ENTRYPOINT ["/usr/local/bin/entrypoint"]
+ENTRYPOINT ["/usr/local/bin/entrypoint"]