use .env file for adding errors and latency

dash-apm-python/background.sh

@@ -5,8 +5,5 @@ mkdir /tracing-workshop
 git clone https://github.com/brettlangdon/distributed-tracing-with-apm-workshop /tracing-workshop
 cd /tracing-workshop
 
-# Try to install yaml_cli helper
-(cd /tmp/ && git clone https://github.com/Gallore/yaml_cli && cd ./yaml_cli && python setup.py install) || true
-
 # Start pulling containers as soon as they load
 docker-compose pull

dash-apm-python/step_5_background.sh

@@ -1,7 +1,3 @@
 #!/usr/bin/env bash
 
-command -v yaml_cli > /dev/null && \
-    yaml_cli -i /tracing-workshop/docker-compose.yml \
-             -o /tracing-workshop/docker-compose.yml \
-             --list-append \
-             -s services:frontend:environment 'WORKSHOP_ADD_ERRORS=true'
+echo "WORKSHOP_ADD_ERRORS=true" >> /tracing-workshop/.env

dash-apm-python/step_6_background.sh

@@ -1,7 +1,3 @@
 #!/usr/bin/env bash
 
-command -v yaml_cli > /dev/null && \
-    yaml_cli -i /tracing-workshop/docker-compose.yml \
-             -o /tracing-workshop/docker-compose.yml \
-             --list-append \
-             -s services:sensors:environment 'WORKSHOP_ADD_LATENCY=true'
+echo "WORKSHOP_ADD_LATENCY=true" >> /tracing-workshop/.env