GRST 159 warn user about fails on user environment setup.sh (#201)

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Fixes #<issue_number_goes_here> 🦕

Author: Arakel2811

retail/interactive-tutorials/user_environment_setup.sh

@@ -61,3 +61,4 @@ gcloud auth activate-service-account --key-file ~/key.json
 # install needed Google client libraries
 cd ~/cloudshell_open/nodejs-retail/samples
 npm install
+'success'