ptm 0.2.6

• Added a NEWS.md file to track changes to the package.

1. compute.dssp() has been deprecated, mkdssp can be used instead.
2. id.features(), pdb.uniprot() and uniprot.pdb() have been re-coded to accommodate the changes introduced into the new UniProt API.
3. get.go() has been sligtly modified to accommodate changes in the EMBL-EBI API.