Don't Allow Drop Tables in Production

## Don't allow --drop-tables in production

### Acceptance Criteria
1. install:run --drop-tables checks the environment for production and doesn't run

### Tasks
- Update the dropTables conditional in `Install\RunInstallCommand::execute()` to account for `$app['env'] === 'production'`

### Additional Notes
- None
"Throw an error" makes it sound like you're throwing an exception.  I think this is over-commenting anyway.  The code itself is readable enough that you don't need it.  Ideally comments shouldn't describe the code, because the code itself should do that.  They should instead describe the intention behind the code .e.g `// Don't allow dropping production tables because that would be bad.`.  In this case, I think that's obvious, so I'd argue you don't need the comment at all.