fix: serialize tx_hashes as hex for json response

[rllola]

closes #22

[bengtlofgren]

These changes are incompatible with the MakeFile. Consider changing the config/Settings.example.toml -> config/Settings.toml or change the MakeFile

[bengtlofgren]

Also on line src/indexer/mod.rs:143 you want to change let fmt_addr = "{}:{} ..." -> let fmt_addr = format!("http://{}:{}", config.tendermint_addr, config.port); or you will get connection issues.

EDIT: I now see this was changed in an older PR. A comment would be very helpful.

[Fraccaman]

you can look at this commit, we just fixed it in our hermes fork: https://github.com/heliaxdev/hermes/commit/9835e7491c9742ff72e10fff01a69f6f3bcff5a2