feat: Rosetta cli test

[bizk]

Closes: #23

Changes:

• Adds Rosetta-cli test to PR process
• Creates a test scenario against cosmos simapp
• Improves some error messages
• Updates on go mod

[raynaudoe]

Just a few minor things to tweak in the configs.

Another thing, the simapp doesn't produce any tx, meaning you have to create them manually (through a script) in order to have some data for rosetta-cli to test with.
This can be done in another PR: take into account what it was done previously here.
The ideal scenario would be having a bunch of accounts, create some transactions between them. (ideally all supported ones by rosetta) and then feed the simapp with that (I don't know the exact steps to do that, but you can explore the repo using the above file at starting point)