prevent double work in the i18n integrity specs
add render nothing to refresh_browsers method
added GIT dependency to VAGRANT guide
Merge pull request #554 from ZogStriP/update-vagrant-guide

added GIT dependency to VAGRANT guide
Merge pull request #553 from buddhamagnet/issue-352-missing-template

Add render nothing to refresh_browsers method
Merge pull request #546 from ZogStriP/improve-i18n-spec-speed

prevent double work in the i18n integrity specs