Moved from Compound to Americano + refactoring

This PR has the same base the other one but with a refactoring.
It also fixes bugs I mentioned in the other PR.

There is still work to do:
* adding tests (and generate a code coverage report to see if we don't test something important)
* the server/lib can be improve/reorganize
* minor improvements to ease development: axon's port as a env variable, indexer's port as a env variable (so it can work nicely outside the vagrant VM)
* I also noted some necessary security improvements and I will create a team note about them