Remove unnecessary files in the results directory

Snakefile

tests/test_alfa/test.sh

tests/test_create_dag_image/test.sh

tests/test_create_rule_graph/test.sh

tests/test_integration_workflow/expected_output.md5

tests/test_integration_workflow/test.local.sh

tests/test_integration_workflow/test.slurm.sh

...t_integration_workflow_multiple_lanes/expected_output.md5

tests/test_integration_workflow_multiple_lanes/test.local.sh

tests/test_integration_workflow_multiple_lanes/test.slurm.sh

workflow/rules/paired_end.snakefile.smk

workflow/rules/single_end.snakefile.smk