[btcsuite/btcd] e6d5c1: Update TravisCI to test against golang 1.5.1.

[Dave Collins]

  Branch: refs/heads/master
  Home:   https://github.com/btcsuite/btcd
  Commit: e6d5c163d5634a9d4dd2de67ab3c4e46fd3cd1ad
      
https://github.com/btcsuite/btcd/commit/e6d5c163d5634a9d4dd2de67ab3c4e46fd3cd1ad
  Author: Dave Collins <da...@conformal.com>
  Date:   2015-09-17 (Thu, 17 Sep 2015)

  Changed paths:
    M .travis.yml
    M goclean.sh

  Log Message:
  -----------
  Update TravisCI to test against golang 1.5.1.

Also, modify the goclean.sh script to quote the test command arguments
and update the vet test to exclude recent false positives.