Replaces Logstash + redis with couch2pg++

[dianabarsan]

Removes Logstash Removes redis Removes redis worker Switches e2e tests from jest to mocha to conform with all of our other repos Adds a refactored version of Couch2pg.

Remaining todos:

• watch changes after initial transfer has finished
• add support for multiple databases
• figure out what we do with deletes

[dianabarsan]

I switched from typescript to javascript for speed of development.

[andrablaj]

107