Pass custom options to Goodtables Inspector

Currently, options passed to the Goodtables' Inspector are hardcoded and can't be passed through the validate method.

I'd like to pass an option here, especially the error_limit value. Otherwise, the default is used and it's sometimes too low (it's 1000).

There is already the option to pass an options dict to the validate method but it's passed to the inspect method of the Inspector, not the constructor.