Pull comments files dynamically

[ArtPoon]

There are some resources that we have obtained once from the Stanford site, e.g., whether mutations are major or minor resistance variants -- ideally sierra-local should check the existing files against online resources and update dynamically when necessary.

[jzpero]

HIVdb page is rendered with React. Should find source data JSON, then read that into a TSV stored locally.

[ArtPoon]

Resource files have been incorporated into the sierra-local repository, but not as a submodule.
We should still revise the updater script to cover these files.

[WilliamZekaiWang]

Added the changes into the dev branch, as well as updates to the unit tests to cover them.