Changes to get the cloud workers to run in our staging environment

Summary:
Summary of the changes:
- renamed some files to es6 to be able to use babel
- only try to create a db folder when we're using sqlite
- drop use of redis
- create a skeleton folder for workers.

Test Plan: Works on staging.

Reviewers: juan

Reviewed By: juan

Differential Revision: https://phab.nylas.com/D3784

pm2-debug-cloud-api.yml

@@ -14,7 +14,7 @@ apps:
       NODE_ENV: 'development'
       HONEY_DATASET: 'n1-cloud-staging'
       HONEY_WRITE_KEY: 'XXXXXXXXXXXXX'
-  - script   : packages/cloud-workers/app.js
+  - script   : packages/cloud-workers/app.es6
     interpreter : node_modules/.bin/babel-node
     watch    : ["packages"]
     name     : workers

pm2-dev.yml

@@ -14,7 +14,7 @@ apps:
       NODE_ENV: 'development'
       HONEY_DATASET: 'n1-cloud-staging'
       HONEY_WRITE_KEY: 'XXXXXXXXXXXXX'
-  - script   : packages/cloud-workers/app.js
+  - script   : packages/cloud-workers/app.es6
     interpreter : node_modules/.bin/babel-node
     watch    : ["packages"]
     name     : workers
@@ -22,5 +22,3 @@ apps:
       DB_ENCRYPTION_ALGORITHM : "aes-256-ctr"
       DB_ENCRYPTION_PASSWORD : "d6F3Efeq"
       NODE_ENV: 'development'
-  - script   : redis-server
-    name     : redis