Add a step to check for migrations and migrate DB if needed

[valeriecodes]

Description of changes

Adds a step to the deploy process which would run migrations on the docker container before it is published.

Note: The original issue requested a test, but I'm not sure how to write an automated test for something like a Makefile task. I also am not sure how best to test locally, beyond running the new task in isolation (which I have done)

Issue Resolved

Fixes #429

[robbkidd]

I recently discovered the db:abort_if_pending_migrations task which pretty much does what it says: exits the rake execution with an error if there are pending migrations.

> rake db:db:abort_if_pending_migrations
You have 10 pending migrations:
  20180129223616 AddGroupToTeamMembers
  20180204235116 AddMoocToCodeSchools
  20180401034441 CreateRoles
  20180408172532 AddRoleIdToAdminUser
  20180416024105 AddEmailToTeamMember
  20180420192231 AddIsPartnerToCodeSchools
  20180422030623 CreateSlackUser
  20180422031009 DropUserSlackId
  20180430161218 AddRepNameToCodeschool
  20180711212702 AddMilitarystatusToUser
Run `rails db:migrate` to update your database then try again.
> echo $?
1

And now that I know about it, of course I want to use it! What do you think about this?

migrate_if_needed:
	bash -c 'docker-compose run ${RAILS_CONTAINER} rake db:abort_if_pending_migrations || docker-compose run ${RAILS_CONTAINER} rake db:migrate'

[robbkidd]

🤔 I'm not super familiar with the deployed production environment. Looking at the bin/publish script has me thinking that this wiring up of a migrate_if_needed action prior to publish would have the migrations occur in an environment that is not production, but rather in a development or CI environment that is doing Docker image tagging and kubernetes service poking.

[valeriecodes]

Gotcha. I thought maybe the docker container that build was run on would then be promoted to production.

[valeriecodes]

If there's someone who could walk me through/explain, I would love to write up documentation.

[apex-omontgomery]

https://github.com/OperationCode/operationcode_backend/wiki/Performing-Production-DB-Migration

Here's a wiki article I created now that our former lead has explained our previous steps, you can look for the details but it's as simple as:

1. connect to kubectl
2. get rails console
3. rake db:migrate