Move GIT_SHA to .env file for dc locally

Author: mcabrams

{{ cookiecutter.project_slug }}/.env.example

@@ -1,3 +1,4 @@
 COMPOSE_PROJECT_NAME={{ cookiecutter.project_slug }}
+GIT_SHA=foobarxyz
 # FILL THESE IN:
 # SENTRY_DSN=

{{ cookiecutter.project_slug }}/docker-compose.test.yml

@@ -50,7 +50,6 @@ services:
       DJANGO_CORS_ORIGIN_WHITELIST: http://localhost:8081,http://client-test:8080
       DJANGO_TRUSTED_ORIGINS: http://localhost:8081,http://client-test:8080
       DJANGO_DISABLE_CSRF: 'True'
-      GIT_SHA: '0123456789'
     tty: true
     stdin_open: true
     ports:

{{ cookiecutter.project_slug }}/docker-compose.yml

@@ -41,7 +41,6 @@ services:
       - ./server/.env
     environment:
       - SENTRY_DSN=${SENTRY_DSN}
-      - GIT_SHA='0123456789'
     tty: true
     stdin_open: true
     ports: