Merge pull request Homebrew#2412 from EricFromCanada/master

Xcode: update supported versions & download URLs for 8.3

Merge pull request Homebrew#2282 from reitermarkus/cask-versions-string

Make `timestamped_versions` return an array of strings.

Merge pull request Homebrew#2013 from reitermarkus/spec-hardware

Convert Hardware test to spec.

Merge pull request Homebrew#1931 from MikeMcQuaid/update-performs-mig…

…rations

update: note migrations may be performed.

Merge pull request Homebrew#1894 from reitermarkus/appcast-checkpoint

Add internal command to calculate appcast checkpoint.

Merge pull request Homebrew#1806 from MikeMcQuaid/audit-virtualenv-se…

…tuptools

audit: check virtualenv and setuptools resource.

Merge pull request Homebrew#1768 from MikeMcQuaid/deprecate-homebrew-…

…versions-devel-only

Deprecate Homebrew/versions, Homebrew/devel-only.

Merge pull request Homebrew#1669 from vladshablinsky/fix_method_depre…

…cated

formulary: call tap not formula

Merge pull request Homebrew#1665 from Homebrew/revert-1592-runtime_de…

…pendencies

Revert "formula: runtime deps of build deps aren't runtime"

Merge pull request Homebrew#1661 from radex/patch-1

Fix typo