SSL certificate problem, when trying to install the libyaml package

I was experiencing the following problem:

Copy It seems your ruby installation is missing psych (for YAML output). 
 To eliminate this warning, please install libyaml and reinstall your ruby

So I tried to install the libyaml package via:

Copyrvm pkg install libyaml

This is when I experienced the SSL certification problem mentioned above. This happens when your RVM certificates have expired. You can fix this by updating them via:

Copy rvm get stable

After doing that curl could verify the SSL certificate and I was able to install the libyaml package.
Finally after reinstalling my ruby via:

Copyrvm reinstall ruby-x.y.z

everything worked fine.