Fix parsing of extra options in tests

This fixes the immediate issue but can be improved (e.g. complaining about
invalid options). Also need to investigate about other sources and whether
they're doing the same thing.
Getting some test coverage around the raised issue.
We need to ensure that we let the user know about the unknown arguments.
The environment variables are parsed in such a way that we will never include options that we don't know about
Added the ability to run rules before parsing the effective options
Added a test to ensure that we are correctly suggesting the incorrectly cased options
Merge pull request #202 from EventStore/extraneous-options

Improve error handling around options parsing