feat: add execution trace for failed target contract deployments

[0xalpharush]

Closes #304. This is progress towards #320 but does not handle the source mapping.

contract Y {
    constructor() public {
        revert();
    }
}

contract X {
    constructor() public {
        new Y();
    }
}

[anishnaik]

A few other things were changed in this PR:

1. The chain setup function now returns an execution trace. This can be logged to all channels so that users are aware where a deployment failure occurred.
2. Fixed a bug in the log buffer.
3. Errors are no longer indented. This makes it look better when printing an execution trace