[conformal/btcutil] 9a9b12: Remove GPG bits from coinset README.md.

[Dave Collins]

  Branch: refs/heads/master
  Home:   https://github.com/conformal/btcutil
  Commit: 9a9b12da003e30499aaa092ca9978c8c18be9714
      
https://github.com/conformal/btcutil/commit/9a9b12da003e30499aaa092ca9978c8c18be9714
  Author: Dave Collins <da...@conformal.com>
  Date:   2014-03-24 (Mon, 24 Mar 2014)

  Changed paths:
    M coinset/README.md

  Log Message:
  -----------
  Remove GPG bits from coinset README.md.

This commit removes the GPG Verification Key section from the new coinset
README.me since the btcutil repo itself is tagged and signed.