Add support for CA key and certificate generation

modd.conf

@@ -1,12 +1,8 @@
-@cert = $HOME/.ssh/hetty_cert.pem
-@key = $HOME/.ssh/hetty_key.pem
 @db = hetty.bolt
 @addr = :8080
 
 **/*.go {
     daemon +sigterm: go run ./cmd/hetty \
-        -cert=@cert \
-        -key=@key \
         -db=@db \
         -addr=@addr
 }