Add gpg to tp Dockerfile for Docker Hub
apt-key requires this package.
FROM ubuntu:bionic
+RUN apt-get update \
+&& apt-get install gnupg -y
+
RUN echo "deb http://repo.sawtooth.me/ubuntu/chime/stable bionic universe" >> /etc/apt/sources.list \
&& (apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 8AA7AF1F1091A5FD \
|| apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 8AA7AF1F1091A5FD) \
