Fix start script

[chancehudson]

The start script leaves processes hanging if an error occurs. We should not recommend users use this script until this is fixed.

[WaterSo0910]

@vimwitch I got the same issue. Is there any alternatives?

[CJ-Rose]

@WaterSo0910 you may need to manually kill any processes left running on ports 3000, 8000, 8545. Then you can start each daemon separately, the instructions for this are in the README at 2.2

[WaterSo0910]

@CJ-Rose Tks for such a helpful answer. I will conduct further research.

[ChialiT]

@AnthonyMadia will you be able to gather more insight about these?
it seems we encounter this type of issue often when user start the create-unirep-app, maybe can start list of problems we have seen, I think some might already fixed.