Remove obsolete tools folder (#149)

## Description of Changes

Not sure when or how this was added (it's not on master), but this
folder shouldn't be here - we have `tools~` instead.

## API

 - [ ] This is an API breaking change to the SDK

*If the API is breaking, please state below what will break*


## Requires SpacetimeDB PRs
*List any PRs here that are required for this SDK change to work*

Author: RReverser