message: Add filters to snapshot preview
diff: @@ -4,11 +4,14 @@ var fs = require('fs')
  var path = require('path')
  var chalk = require('chalk')
  +var filter = process.argv[2]
  +
  function show (result) {
  Object.keys(result).sort().reverse().forEach(file => {
  var test = file.replace(/\.test\.js\.snap$/, '')
  result[file].split('exports[`')
  .filter(str => str.indexOf('// ') !== 0)
  + .filter(str => !filter || str.indexOf(filter) !== -1)
  .forEach(str => {
  if (str.trim().length === 0) return
  var parts = str.replace(/"\s*`;\s*$/, '').split(/`] = `\s*"/)
  