Dockerfile in fir-cli-2.0.12 vs Dockerfile in fir-cli-2.0.13

@@ -1,5 +1,5 @@
-FROM ruby:2.6.1
+FROM ruby:2.7.1
 RUN gem install bundler
 ENV LANG=C.UTF-8 
 ENV WORKDIR=/fir-cli
 ENV HOME=/fir-cli
 RUN mkdir -p $WORKDIR