[conformal/btcec] e6011e: Add godoc reference badge to README.md.

[Dave Collins]

  Branch: refs/heads/master
  Home:   https://github.com/conformal/btcec
  Commit: e6011eaa49e188695efcabbd102ce93cbf5b6558
      
https://github.com/conformal/btcec/commit/e6011eaa49e188695efcabbd102ce93cbf5b6558
  Author: Dave Collins <da...@conformal.com>
  Date:   2014-08-10 (Sun, 10 Aug 2014)

  Changed paths:
    M README.md

  Log Message:
  -----------
  Add godoc reference badge to README.md.