This commit adds CSRF protection based on the gorilla/csrf package.
Node dependencies have been updated.
Logging uses sirupsen/logrus for log level support now.
This commit implements a basic static HTML page that uses Bootstrap 4
for layout and node-forge to generate a RSA key pair and a certificate
signing request. The subject of the CSR and the key size can be chosen
by the user.
The implementation uses gulp to collect static assets and to allow
bootstrap customization.
