Remove maximum version for symfony/config and symfony/dependency-injection

I don't think there's any reason to limit these dependencies to <2.3.0. I've tested with 2.3.x and everything seems to work fine. I see no reason why 2.4 and higher wouldn't work as well.
Update UIBusinessSelectorContext.php

add new selector and step. 

We need this library to also be able just to look for text on a page. So domain 1 is in language foo and domain 2 is in language bar but the both have the business need to have "Disclaimer"

So the user can make a token for domain 1
Disclaimer: "Use site at own risk"

And the for domain 2
Disclaimer: "malja' Daq DeSDu' bISuDqu' 'e' lach'eghDI'"
Update UIBusinessSelectorContext.php

bug did not return an exception if the element was not found
Merge pull request #14 from wildlyinaccurate/patch-1

Remove maximum version for symfony/config and symfony/dependency-injection
Merge pull request #17 from alnutile/patch-1

Update UIBusinessSelectorContext.php