Revert "chore(ionicons): remove the import of ionicons css" (ionic-team#680)

Author: danbucholtz

config/sass.config.js

@@ -42,6 +42,7 @@ module.exports = {
  */
  includePaths: [
  'node_modules/ionic-angular/themes',
+ 'node_modules/ionicons/dist/scss',
  'node_modules/ionic-angular/fonts'
  ],