Update code checks for burnham and burnham-bigquery 🤖

[hackebrot]

We recently merged a pull-request from Dependabot that introduced incompatible dependencies for burnham (#84). As a consequence we cannot push new Docker images to GKE because the Docker workflow fails.

@jklukas correctly pointed out in #88 (comment) that we need checks that exercise the build workflow.

We currently run the following code checks on CircleCI (see config file):

• flake8
• mypy
• pytest

All of these run in a tox environment. As a first step, I suggest we update the installation step to also install from requirements.txt so that any dependency conflict is detected there. I also think we should build the Docker images for pull-requests.

According to the documentation of the CircleCI orb that we use for the Docker workflows, we should be able to add a gcp-gcr/build-image step. Ideally it will only run if the respective subdirectories are modified.

[b4handjr]

Do we want to do a pip install for each tox job? If we just want to check if everything installs maybe we can have a job just to install the requirements.txt

[hackebrot]

We probably don't need to install the packages for the flake8 environment, so we can add a skip_install = true to the tox config there. For mypy and py37 we need to install the same packages as we install in Dockerfile plus any test dependencies.

[b4handjr]

Per our discussion earlier today, should I add the install to tox under the commands section? This has worked locally for me and it gets around the hash error from pip.

[hackebrot]

Yes, that'd be great! 👍