When downloading from remote site anything can happen, installer build and installer itself should verify checksum for downloaded resources.

• add method createSHA256(file) into gulpfile.js to create sha256 checksum for file
• here is an example http://www.hacksparrow.com/how-to-generate-md5-sha1-sha512-sha256-checksum-hashes-in-node-js.html
• then we will need to create SHA256 for vagrant and virtualBox or download them if they are available
• and then we can skip downloading if it's already on disk

Request comes from Product Security team.