Migrate Truffle project to 4.x for testing purposes

[mconnelly8]

[nikoulai]

The PR in the truffle repo: ConsenSys-archive/truffle#6013

[nikoulai]

In a couple of instances dom had to be added as a required lib at the package, because the type RequestInit couldn't be found. This solution was proposed here. (Also see this)
IMO users should just get web3js without having to make any changes in their libs and this case should be handled by our side.

[jdevcs]

This issue was created for older 4.x testing with truffle, and next RC/Full release should be tested and tracked under #6144