[conformal/btcutil] cd8397: Update TravisCI to use goclean script.

[Dave Collins]

  Branch: refs/heads/master
  Home:   https://github.com/conformal/btcutil
  Commit: cd83976947245e17f4c429e791291ac649c07db9
      
https://github.com/conformal/btcutil/commit/cd83976947245e17f4c429e791291ac649c07db9
  Author: Dave Collins <da...@conformal.com>
  Date:   2014-12-20 (Sat, 20 Dec 2014)

  Changed paths:
    M .travis.yml

  Log Message:
  -----------
  Update TravisCI to use goclean script.