#24 Round-off bug

Using the following generator configuration, the plugin seems to not adding values properly:

    - COBBLESTONE:96.41
    - COAL_ORE:1.0
    - IRON_ORE:0.8
    - GOLD_ORE:0.6
    - LAPIS_ORE:0.5
    - REDSTONE_ORE:0.3
    - EMERALD_ORE:0.2
    - NETHER_QUARTZ_ORE:0.12
    - DIAMOND_ORE:0.07