Add more integration tests

[gromdimon]

Is your feature request related to a problem? Please describe.
After implementation of VCEPs we should add more integration tests.

Describe the solution you'd like
Add integration tests as it was done for AutoPM1
Look for tests.integ.test_integ_pm1.py and tests.assets.integ.pm1.csv

Describe alternatives you've considered
N/A

Additional context
Add at least 1 positive and 1 negative example for each gene from the VCEPs.