Fix GPG key error

Author: Will Feng

.circleci/config.yml

@@ -6,11 +6,24 @@ install_official_git_client: &install_official_git_client
  sudo apt-get -qq update
  sudo apt-get -qq install openssh-client git
 
+# This system setup script is meant to run before the CI-related scripts, e.g.,
+# installing Git client, checking out code, setting up CI env, and
+# building/testing.
+setup_linux_system_environment: &setup_linux_system_environment
+ name: Set Up System Environment
+ no_output_timeout: "1h"
+ command: |
+ set -e
+ # Set up CircleCI GPG keys for apt, if needed
+ curl -L https://packagecloud.io/circleci/trusty/gpgkey | sudo apt-key add -
+
 pytorch_tutorial_build_defaults: &pytorch_tutorial_build_defaults
  machine:
  image: default
  steps:
  - checkout
+ - run:
+ <<: *setup_linux_system_environment
  - run:
  name: Set Up CI Environment
  no_output_timeout: "1h"