How to fix SSL Cert errors on vagrant provision

How to fix the SSL certificate errors.

When the provision fails, SSH into your vagrant and create two files:
/etc/gemrc
~/.gemrc

These contain one line:
:ssl_verify_mode: 0

Next, run this command:
sudo /opt/puppetlabs/puppet/bin/gem update --system

Wait for that to finish and exit your box.
Run
vagrant provision

Now it should continue.