Test coverage

[cspotcode]

compare node and node -r source-map-support/register to make sure output matches

process.on('exit') w/graceful termination
process.on('exit') w/unhandled exception
process.on('exit') w/unhandled promise rejection
colorized output
colorized output when stdout is piped
non-colorized output when stderr is piped
async stack frames formatted with async prefix