Some tools for working with MHC structures

1. Install Chimera, Scwrl and Brikard and specify their location in vars.json.tpl (if on Seawulf, no modification needed)
2. Run ./bootstrap.sh
3. source activate.sh
4. pytest -v

So far usable and covered with tests are:

• from mhc_tools.sampling.generate_peptides import PeptideSampler
• from mhc_tools.sampling.template_modelling import TemplateModeller
• from mhc_tools.mhc_peptide import BasePDB

The rest is in development