Enable Travis-CI for this Project to Confirm Tests are Passing

[nelsonic]

Tests for #2 (Daniel's PR) currently pass on my Localhost:

But we cannot "know" this without checking out the branch and running the tests on localhost ...

Todo

• Using https://github.com/dwyl/phoenix-ecto-encryption-example/blob/master/.travis.yml as an example, create a .travis.yml file for this project.
  • create append_only user on Travis-CI before attempting to run tests
    see: Enable Travis-CI for this Project to Confirm Tests are Passing #3 (comment)
• Add any necessary lines to mix.exs so that we can run coverage using :excoveralls
  • using example: https://github.com/dwyl/phoenix-ecto-encryption-example/blob/master/mix.exs#L50
• Enable the project on Travis-CI.org so tests are run on every commit/push.

Thanks! 👍

[nelsonic]

Got mix cover working on localhost on tutorial branch:

[nelsonic]

https://travis-ci.org/profile/dwyl enabled:

see: https://travis-ci.org/dwyl/phoenix-ecto-append-only-log-example/builds

[nelsonic]

Build fails on Travis-CI because it is expecting a "append_only" Postgres user to exist:
https://travis-ci.org/dwyl/phoenix-ecto-append-only-log-example/builds/431146775#L604

So we need to create the user on Travis-CI before attempting to run the tests.

[nelsonic]

Thanks to: https://stackoverflow.com/questions/42177055/how-to-set-up-travis-ci-and-postgresql-using-custom-db-credentials

it's relatively easy to add a before_script: to the .travis.yml file.
Trying it now:

before_script:
  - psql -c "CREATE USER append_only WITH PASSWORD 'postgres';" -U postgres
  - psql -c "ALTER USER append_only CREATEDB;" -U postgres

[nelsonic]

Build passing: https://travis-ci.org/dwyl/phoenix-ecto-append-only-log-example/builds/431336390

We can work on improving the coverage after the tutorial is more complete. 👍