Ran into the excon/openssl error certificate verify failed (OpenSSL::SSL::SSLError) Unable to verify certificate.
After reading through a few posts, trying different solutions, here are the steps that resolved the issue with regards to my particular needs. Final main source at the bottom.
brew doctor
brew update openssl
rvm get stable
rvm install ruby-2.1.9 --with-openssl-dir=`brew --prefix openssl`