tests: fix test breakage in Github CI.

Fix tests not working in Github. They were failing because the latest
version of Webpack needs a version of Node newer than the version in
shipped Ubuntu 20.04.

Also fix the Docker build failing because of the system timezone
database not being installed in Ubuntu 20.10.

.github/workflows/test.yaml

@@ -12,7 +12,7 @@ on:
 jobs:
   test:
     runs-on: ubuntu-latest
-    container: ubuntu:20.04
+    container: ubuntu:20.10
 
     defaults:
       run:

Gemfile

@@ -45,6 +45,7 @@ gem 'pundit'
 gem 'mail'
 gem 'nokogiri'
 gem 'view_component', require: 'view_component/engine'
+gem 'tzinfo-data'
 
 group :production, :staging do
   gem 'unicorn', :platforms => :ruby

Gemfile.lock

@@ -387,6 +387,8 @@ GEM
     thor (1.1.0)
     tzinfo (2.0.4)
       concurrent-ruby (~> 1.0)
+    tzinfo-data (1.2021.1)
+      tzinfo (>= 1.0.0)
     unf (0.1.4)
       unf_ext
     unf_ext (0.0.7.7)
@@ -485,6 +487,7 @@ DEPENDENCIES
   streamio-ffmpeg
   stripe
   stripe-ruby-mock
+  tzinfo-data
   unicorn
   unicorn-worker-killer
   view_component

config/docker/Dockerfile.danbooru

@@ -1,4 +1,4 @@
-FROM ubuntu:20.04 AS build
+FROM ubuntu:20.10 AS build
 
 RUN \
   apt-get update && \
@@ -40,7 +40,7 @@ ARG RAILS_ENV=production
 RUN bin/rails assets:precompile && ln -sf packs public/packs-test
 RUN rm -rf node_modules log tmp && mkdir log tmp
 
-FROM ubuntu:20.04
+FROM ubuntu:20.10
 
 RUN \
   useradd --create-home --user-group danbooru && \