Add custom output formattin

[stefanbuck]

var prettyStdOut = new PrettyStream({
  mode: function(time, level, name, host, src, msg, extras, details) {
    return util.format('%s: %s%s\n%s', level, msg, extras, details);
  }
});

[coveralls]

Coverage decreased (-0.79%) when pulling 24c3de0 on stefanbuck:master into 3be44f0 on mrrama:master.