Fix: base image tag

Dockerfile

@@ -3,7 +3,7 @@ ADD package.json yarn.lock /build/
 ADD package.json yarn.lock /app/
 RUN cd /build && yarn --production=false && cd /app && yarn --production=true
 
-FROM node:lts-slim
+FROM node:14-slim
 RUN apt-get update && apt-get install -y curl iputils-ping && apt-get clean
 ENV TERM=xterm
 ADD fonts.conf /etc/fonts/