Backport UCSCParser, UCSC_human_parser and UCSC_mouse_parser from ensembl-xref
Created by: mkszuba
Description
Port changes made to UCSCParser (as well as the two thin wrappers around it used for human and mouse) in ensembl-xref, including unit tests, back to ensembl:feature/xref_sprint.
Use case
See ENSCORESW-3231. Originally worked on by Mag.
Benefits
Salvage more work from the 2018 xref sprint. Actually get UCSC xrefs back (their file format has changed) once ensembl:feature/xref_sprint has been merged into master.
Possible Drawbacks
Increased test-suite run time (note: Travis does not automatically execute tests from misc-scripts/xref_mapping yet).
Testing
Have you added/modified unit tests to test the changes?
Yes.
If so, do the tests pass/fail?
They pass.
Have you run the entire test suite and no regression was detected?
Yes (including tests from misc-scripts/xref_mapping), no regression detected.