upgrade: fetch all formulae before installing

[FnControlOption]

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[MikeMcQuaid]

Looking good so far! Nothing to do here but in future reference you can just force push to an existing PR instead of opening a new one.

[MikeMcQuaid]

Looks good! One naming thought.

[MikeMcQuaid]

Suggested change

	def fetch_formula_installer(
	def fetched_formula_installer(

or

Suggested change

	def fetch_formula_installer(
	def fetch_and_return_formula_installer(

[MikeMcQuaid]

Thanks again @FnControlOption!

[FnControlOption]

Why rename to create_and_fetch_formula_installer when fi.fetch happens outside the method?

[MikeMcQuaid]

@FnControlOption I misread your most recent changes, sorry 🤦🏻. I can open a PR to revert or you can, what would you rather?