LENS-1387: Move Lens compile & target version to Java 8
LENS-1387: Move Lens compile & target version to Java 8

archanah24/lens,sushilmohanty/incubator-lens,sushilmohanty/incubator-lens,archanah24/lens,sushrutikhar/grill,sushrutikhar/grill,sushrutikhar/grill,sushrutikhar/grill,archanah24/lens,archanah24/lens,sushilmohanty/incubator-lens,sushrutikhar/grill,archanah24/lens,sushilmohanty/incubator-lens,sushilmohanty/incubator-lens