Reimplement PAINTOR

[bschilder]

• Now working with echoverse.
• Generalized to any data input type (GWAS/QTL/TWAS)
  to avoid hard-coded args.
• Streamlined functions and reduced clutter.
• Automated installation of PAINTOR. PAINTOR: installation issues #12
• Added unit tests.
• Get/query full PAINTOR annotations Add large annotations echoannot#10
• User-supplied annotations via annot
• xgr/roadmap annotations.

[bschilder]

Currently stuck on the issues of hosting individual files due to a bug in Zenodo:
zenodo/zenodo#2131
Haven't heard back from the Zenodo team in a while.

If Zenodo doesn't work, will upload the files to another public facing server and distribute from there.