Python tests for microbiorust-py

**Is your feature request related to a problem? Please describe.**
Currently there are only Rust tests for microbiorust-py where we test if the functions are attached to the module

**Describe the solution you'd like**
We need some actual python tests for the functions #pytest 

write python tests for each of gbk, embl, align, seqmetrics 

- this is required before further improvements


