Dockerfile in sidekiq-web_custom-0.4.0 vs Dockerfile in sidekiq-web_custom-0.4.1

- old
+ new

@@ -1,5 +1,5 @@
-FROM ruby:2.5.5
+FROM ruby:2.7.5
 RUN cd /tmp && curl -L --output ghr.tar.gz https://github.com/tcnksm/ghr/releases/download/v0.12.0/ghr_v0.12.0_linux_amd64.tar.gz && \
     tar -xzvf ghr.tar.gz && chmod +x ghr_v0.12.0_linux_amd64/ghr && mv ghr_v0.12.0_linux_amd64/ghr /usr/local/bin/ghr && rm -rf /tmp/*
 
 WORKDIR /gem
 COPY Gemfile /gem/Gemfile