Initialize the testnode from a log

$ cargo run --bin silk-genesis-file-demo > demo-genesis.json
$ cat demo-genesis.json | cargo run --bin silk-genesis-block > demo-genesis.log
$ cat demo-genesis.log | cargo run --bin silk-testnode

src/lib.rs

@@ -14,5 +14,6 @@ extern crate ring;
 extern crate serde;
 #[macro_use]
 extern crate serde_derive;
+extern crate serde_json;
 extern crate sha2;
 extern crate untrusted;