Rails 5.2 dual boot

[yuenmichelle1]

Rails 5.2 dual boot
Other Changes

• From Rails 5.1 to 5.2, there was a change in db:load_config task which is a task that db:create depends on. db:load_config now depends on the environment, which would load the application (especially our concerns [used in serializers and models eg. TalkSerializer and BooleanCoercian] to load, which would trigger a DB connection that can't be established because the DB does not exist yet (which is why we run db:create to create the db, but b/c of this change to db:load_config, db:create won't work) . This is a known issue in Rails 5.2+ and can be mitigated see: https://stackoverflow.com/questions/72147515/rails-5-2-load-order-breaks-dbcreate which should also reference the Rails PR that introduce this change
• We update the RakeFile to get db:create and other rake tasks to succeed, in order to get our CI tests and local dev setup still functional.
• For FDW Models, primary_key must be specified for each model for our specs to run. See: https://gist.github.com/westonganger/79683fad3e4ec3b10105e40d3069a18e

[yuenmichelle1]

Hey @Tooyosi , Let me know if you have any questions on this review. It's fairly straight forward sans some finagling that needed to be done due to changes from Rails 5.1 -> 5.2.
Best way to test the rake changes is to start with a clean local dev environment and try to run talk-api local dev setup for 5.1 and 5.2 and run specs.