Tests fail for build 19 (after adding 3D Datasets for MRI)

[asciidiego]

Tests seem to fail at CircleCI. It seems that the pytest module could not be found inside the testing server virtual environment. As shown here:

#!/bin/bash -eo pipefail
. venv/bin/activate
mkdir test-reports
# Skip other tests for the moment, only run test_models.
pytest -v --junitxml=test-reports/junit.xml tests/test_models.py
/bin/bash: line 3: pytest: command not found
Exited with code 127

It seems that we only need to change the CircleCI configuration so that it uses the requirements.txt or the test-requirements.txt file so that pytest module is correctly installed.

Also, why do we have separate requirements.txt files for testing vs production environments? Shouldn't we emulate as best as we can the production environment by using a single requirements.txt file—or for that matter a single conda environment?

[asciidiego]

Also, even though the tests failed after adding the 3D datasets and 3D U-Net models by @morvan-s , it seems that the issue is completely irrelevant to his additions; however, shouldn't we (or him, since he was the author of the code) add tests that cover the 3D datasets and models?