Fix expired signature for yarn

build/Dockerfile

@@ -3,6 +3,10 @@ FROM nikolaik/python-nodejs:python3.7-nodejs12
 ENV PATH "/root/.local/bin:$PATH"
 ENV NODE_PATH "/usr/lib/node_modules"
 
+ENV YARNKEY=yarn-keyring.gpg
+RUN curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | gpg --dearmour -o /usr/share/keyrings/$YARNKEY && \
+  echo "deb [signed-by=/usr/share/keyrings/$YARNKEY] https://dl.yarnpkg.com/debian stable main" | tee /etc/apt/sources.list.d/yarn.list
+
 RUN npm install -g postcss-cli@^6.1.3 autoprefixer@^9.7.0 svgo@^1.3.0 cssnano@^4.1.10 \
   && apt-get update \
 	&& apt-get install -y libjpeg-progs optipng \