Upgrade dependencies to resolve 70 vulnerabilities

Expand helper test coverage with mapParents, reduceArrayToObj, and buildRefList

Fix branch name parsing, stdout flushing, and shared state mutation

0.8.1

Fix multiple dependency vulnerabilities

Upgrade npm dependencies

0.8.0

Fix vulnerabilities through `npm audi fix`

Rename `getAttachment` to `getHEADTarget`

Simplify processing by avoiding intermediate properties

Add a lot of missing code comments

Reduce sha1sum to simplier reference

Simplify buildSchema method

Reduce try/catch scope

Rebuild method for gathering refs