Add env var pass through for allauth provider secrets (readthedocs#209)

* Add env var pass through for allauth provider secrets

This has a matching community PR to support settings these from the
host. This is similar to the pattern we're using for Stripe secrets

* Drop unused env var pass throughs

* Drop bitbucket provider env var passthrough

dockerfiles/docker-compose.yml

@@ -109,6 +109,14 @@ services:
       - RTD_STRIPE_SECRET
       - RTD_STRIPE_PUBLISHABLE
       - RTD_DJSTRIPE_WEBHOOK_SECRET
+      - RTD_SOCIALACCOUNT_PROVIDERS_GITHUB_CLIENT_ID
+      - RTD_SOCIALACCOUNT_PROVIDERS_GITHUB_SECRET
+      - RTD_SOCIALACCOUNT_PROVIDERS_GITLAB_CLIENT_ID
+      - RTD_SOCIALACCOUNT_PROVIDERS_GITLAB_SECRET
+      - RTD_SOCIALACCOUNT_PROVIDERS_BITBUCKET_OAUTH2_CLIENT_ID
+      - RTD_SOCIALACCOUNT_PROVIDERS_BITBUCKET_OAUTH2_SECRET
+      - RTD_SOCIALACCOUNT_PROVIDERS_GOOGLE_CLIENT_ID
+      - RTD_SOCIALACCOUNT_PROVIDERS_GOOGLE_SECRET
     stdin_open: true
     tty: true
     networks: