Consider defining the skeleton_key and chain_id constants for private mirrornet purposes
Agreeing on a fixed values for these variables for testing purposes should be a beneficial solution because we won't have to pass them every time to run a node.
For e.g. now, we have to take into account that a different key can be used for building and replay than for testing and we need to provide the possibility of passing it there, should be better to define a constant in both places
Edited by Mateusz Żebrak