If you encounter the following issue:
Follow the 'Manual solution to SSL issue' part on this page: github
ERROR: Could not find a valid gem 'xxxx' (>= 0), here is why: Unable to download data from https://rubygems.org/ - SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed (https://api.rubygems.org/latest_specs.4.8.gz)
Follow the 'Manual solution to SSL issue' part on this page: github