Reduce collection create fee

In ZooPet creating a collection requires a fee of 2000 ZOO to be paid per each creation. This is both an anti-spam and deflationary measure. Raised funds are being locked in dedicated wallet and thus are not circulating (i.e. cannot be sold). We can reduce collection create fee from 2000 to 1000 ZOO. This will affect positively on collection creation, but also will slow down the process of taking ZOO out of circulation.