Increment version to 5.3.1.8
Increment version to 5.3.1.8

caraka/gridcoinresearch,gridcoin/Gridcoin-Research,gridcoin/Gridcoin-Research,caraka/gridcoinresearch,caraka/gridcoinresearch,gridcoin/Gridcoin-Research,gridcoin/Gridcoin-Research,caraka/gridcoinresearch,caraka/gridcoinresearch,caraka/gridcoinresearch,gridcoin/Gridcoin-Research,gridcoin/Gridcoin-Research