Update shadow to 1.2.2 for Gradle 2.5 compatibility
Update shadow to 1.2.2 for Gradle 2.5 compatibility

kenzierocks/Sponge,SpongePowered/SpongeForge,joseph00713/Sponge,DDoS/Sponge,kenzierocks/SpongeForge,DDoS/Sponge,joseph00713/Sponge,DDoS/SpongeForge,Istar-Eldritch/Sponge,kenzierocks/SpongeForge,SpongePowered/SpongeForge,kenzierocks/Sponge,Istar-Eldritch/Sponge,DDoS/SpongeForge