check JTable instead of JLabel in GUI now.
replace JLabel by simple JTable .
new end to end test

new sniperWinsAnAuctionByBiddingHigher test to check the row of
SnipersTable.
complie pass with adding SniperState.
add enum Column
add SnipersTableModelTest
add Apache Common Lang package for SniperState
rename SniperState to SniperSnapshot.