Dockerfile in thinreports-0.11.0 vs Dockerfile in thinreports-0.12.0

@@ -1,5 +1,5 @@
-FROM ruby:2.7.1
+FROM ruby:3.0.0
 
 RUN apt-get update -qq && apt-get install -y build-essential xvfb
 
 # Install diff-pdf
 WORKDIR /tmp