Update download url for version 1.3.1

Signed-off-by: Rogerio Prado de Jesus <rogeriopradoj@gmail.com>
Update vagrant package version for 1.3.1

Signed-off-by: Rogerio Prado de Jesus <rogeriopradoj@gmail.com>
Include contributors in README.md

Signed-off-by: Rogerio Prado de Jesus <rogeriopradoj@gmail.com>