epss: add NewFactory()

[daynewlee]

No description provided.

[crozzy]

How are you calling this? Distinct from how Clair instantiates it?

[daynewlee]

How are you calling this? Distinct from how Clair instantiates it?

Something like this

updates.WithFactories(map[string]driver.UpdaterSetFactory{
			"epss": epss.NewFactory(),
		}),

[crozzy]

I'm kind of on the fence if this is needed or can be done by the caller. I suppose it is a helper function that allows for easier API interaction even if it's not directly used by Clair or Claircore.

[RTann]

From what I can tell, it's not required, as I believe you can just do WithOutOfTree(epss.UpdaterSet()) but then the configuration is a bit awkward (you'd have to map the configuration with the name outOfTree)