Puphpet — vagrant provision failure on Ruby gem deep_merge

If you’re running into this error provisioning your puphpet vagrant box:

==> machine2: ERROR: Could not find a valid gem 'deep_merge' (= 1.0.1), here is why:
==> machine2: Unable to download data from https://rubygems.org/ - SSL_connect returned=1 errno=0 state=error: certificate verify failed (https://api.rubygems.org/specs.4.8.gz)
==> machine2: ERROR: Could not find a valid gem 'activesupport' (= 4.2.6), here is why:
==> machine2: Unable to download data from https://rubygems.org/ - SSL_connect returned=1 errno=0 state=error: certificate verify failed (https://api.rubygems.org/specs.4.8.gz)
// etc

Fix it quickly and easily with this helpful paste. Thank you junkystu!