refactor(Audit): Convert to ES5 class (#2157)
refactor(Audit): Convert to ES5 class (#2157)

This patch refactors the `Audit` into a proper ES5 class. This improves readability while keeping the same functional behavior.
dequelabs/axe-core,dequelabs/axe-core,dequelabs/axe-core,dequelabs/axe-core