test(homebrew): tighten Formula/gander.rb test to --version once next release ships

[scott]

Summary

Formula/gander.rb at gandermd/homebrew-gander currently asserts the installed binary via:

test do
  assert_match "render Markdown", shell_output("#{bin}/gander --help")
end

The intent (per #46) was:

test do
  assert_match version.to_s, shell_output("#{bin}/gander --version")
end

The looser assertion is a stop-gap: the v0.11.0 binary predates the --version / gander version change in PR #58. PR #58 will ship in the next release (v0.12.0 or later). Once that release is tagged and the formula is bumped via scripts/bump-homebrew.sh, the test can use the original --version assertion — both tighter and more obviously version-aware.

Acceptance criteria

• Confirm the next release (≥ v0.12.0) ships with --version / gander version
• During the bump PR opened by scripts/bump-homebrew.sh <version>, edit Formula/gander.rb to:

  test do
    assert_match version.to_s, shell_output("#{bin}/gander --version")
  end

• brew audit --strict --new --tap=gandermd/gander gander exits 0
• brew test gandermd/gander/gander exits 0

Notes

• version is auto-derived from the URL (no explicit version "X.Y.Z" line in the formula), so version.to_s continues to track the bumped value.
• This change is a single-line edit in the bump PR; no separate release plumbing needed.

[scott]

Done in PR #61 (and merged to the tap via gandermd/homebrew-gander#2). The formula's test block now asserts gander --version and brew test gandermd/gander/gander passes against v0.12.0.