A few cert-issuer bugfixes in support of Ethereum issuance, and development environments

Just a quick note that some fixes have been integrated into the cert-issuer project. These changes attempt to address a few problems that people were having when trying to set up Ethereum issuances, as well as a general fix to make it easier to run in a development environment out of the box (hopefully, we got rid of that Module not found: bitcoin.rpc error).