Use go get instead of replace directives to downgrade dependencies in monogen

[joshklop]

Right now, we downgrade a number of dependencies using replace directives. We should do this using the go command instead of replace directives.

[Jesserc]

@joshklop please can you expand on this?

[joshklop]

I think some of the replace directives are unnecessary, like this one:

monomer/monogen/monogen.go

Line 260 in 20483a9

github.com/btcsuite/btcd/btcec/v2 v2.3.4 => github.com/btcsuite/btcd/btcec/v2 v2.3.2

We should instead use go get to downgrade the package instead. See the gocmd package in the github.com/ignite/cli module for a way to easily use the go command from a Go program.

[pri-3x]

@joshklop PR for this issue: #250